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Full text of "Proceedings of the American Society of Agronomy"

OAK ST. HDSF 



THE UNIVERSITY 
0F ILLINOIS 
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cop. 3 



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JOURNAL 

OF THE 

AMERICAN SOCIETY 
OF AGRONOMY 



VOLUME 11 



1919 



PUBLISHED BY THE SOCIETY 



PRESS OF 
THE NEW ERA PRINTING COMPANY 
LANCASTER. PA. 



DATES OF ISSUE. 



Pages 1-48, January 15, 1919. 
Pages 49-80, February 15, 1919. 
Pages 81-128, March 29, 1919. 
Pages 129-172, April 30, 1919. 
Pages 173-220, June 5, 1919. 
Pages 221-268, September 15, 1919. 
Pages 269-^308, October 15, 1919. 
Pages 309-332, November 15, 1919. 
Pages 333-356, December 31, 1919. 



AIV\ R 



CONTENTS. 

J) 



No. I. JANUARY. 

Page. 

ToTTiNGHAM, W. E. — A Preliminary Study of the Influence of Chlorides 

on the Growth of Certain Agricultural Plants i 

) Arny. A. C, and Garber, R. J. — Field Technic in Determining Yields of 

^ Plots of Grain by the Rod-Row Method (Figs, i and 2) 33 

Agronomic Affairs, 

Outlook for 1919 48 

Delay in December Number 48 

No. 2. FEBRUARY. 

Wright, R. C. — Nitrogen Relations of Certain Crop Plants when Grown 

Alone and in Association (PI. i and Figs. 3-6) 49 

Hayes, H. K., and Stakman, E. C. — Rust Resistance in Timothy 67 

NoYES, H. A.— The Effect of Heat on the Lime Requirements of Soils 70 

Warburton, C. W. — The Occurrence of Dwarf ness in Oats (PI. 2) 72 

Cutler, G. H.— A Dwarf Wheat 76 ■ 

Agronomic Affairs. 

Membership Changes 78 

Notes and News 79 

No. 3. MARCH. 

Arxy, a. C, and Steinmetz, F. H. — Field Technic in Determining Yields 

of Experimental Plots by the Square-Yard Method (Figs. 7-9) 81 

Carrier, Lyman. — A Reason for the Contradictory Results in Corn Ex- 
periments 106 

Butler, O. — The Effect of the Environment on the Loss of Weight and 

Germination of Seed Potatoes during Storage 114 

Burgess, J. L.— Relation of Varying Degrees of Heat to the Viability of 

Seeds 118 

Winters, R. Y. — Community Cotton Improvement in North Carolina 121 

Agronomic Affairs. 

Membership Changes 125 

Report of the Secretary-Treasurer for 1918 126 

No. 4. APRIL. 

Shepperd, J. H. — Carrying Capacity of Native Range Grasses in North 

Dakota (PI. 3-5 and Fig. 10) 129 

Leighty, C. E., and Hutcheson, T. B.— On the Blooming and Fertilization 

V 



vi CONTENTS. 

Page. 

of V/heat Flowers (Figs, ii and 12) 143 

Stewart, George. — The Varieties of Small Grain and the Market Classes 

of Wheat in Utah 163 

Agronomic Affairs. 

Membership Changes 170 

Notes and News 171 

No. 5. MAY. 

Garber, R. J,, and Olsen, P. J. — A Study of the Relation of Some Morpho- 
logical Characters to Lodging in Cereals (PI. 6 and Figs. 13 and 14) 173 
Waldron, L. R., and Clark, J. A. — Kota, A Rust-Resisting Variety of 

Common Spring Wheat (PI. 7) 187 

Bolley, H, L. — Official Field Crop Inspection 196 

Carrier, Lyman. — American Husbandry, a Much Overlooked Publication. 206 

Love, H. H. — The Experimental Error in Field Trials 212 

Agronomic Affairs. 

Membership Changes 217 

Notes and News 217 

No. 6. SEPTEMBER. 

Oakley, R. A. — The Work of the Committee on Seed Stocks 221 

BiGGAR, H. Howard. — The Relation of Certain Ear Characters to Yield in 

Corn 230 

KiESSELBACH, T. A. — Experimental Error in Field Trials 235 

Kiesselbach, T. a. — Plat Competition as a Source of Error in Crop Tests. 242 
Hendry, G. W. — Climatic Adaptations of the White Tepary Bean (PI. 8) . . 247 
Karraker, p. E. — What is the Value of the Usual Laboratory Work Given 

in General Soils Courses ? 253 

Karper, R. E., and Conner, A. B. — Natural Cross-Pollination in Milo .... 257 

Waldron, L. R. — Cross-Pollination in Alfalfa 259 

Agronomic Affairs. 

Notes and News 267 

No. 7. OCTOBER. 

Sewell, M. C. — Tillage : A Review of the Literature 269 

Stakman, E. C, Hayes, H. K., Aamodt, Olaf S., and Leach, J. G. — Con- 
trolling Flax Wilt by Seed Selection (PI. 9) 291 

Cook, O. F. — Experiments in Spacing Cotton 299 

Butler, O. — Ef¥ect of Wounds on Loss of Weight in Potatoes 304 

Agronomic Affairs. 

Membership Changes 306 

Notes and News 307 

No. 8. NOVEMBER. 

Hayes, H. K., and Garber, R. J. — Synthetic Production of High-Protein 

Corn in Relation to Breeding (PI. 10) 309 

Bear, Firman E., and Royston, J. R. — Nitrogen Losses in Urine 319 



CONTENTS. 



vii 



Page. 

Hartwell, Burt L. — The Manurial Value of a Modification of Orthoclase- 



Bearing Rock where only Potassium Was Deficient 327 

Agronomic Affairs. 

Membership Changes 33<5 

Notes and News 33 1 

No. 9. DECEMBER. 

LiPMAN, J. G. — Taxing the Air for Increased Food Production (Presi- 
dential Address) 333 

Piper, C. V. — The Words Productivity, or Productiveness, and Fertility as 

Applied to x\griculture 342 

Agronomic Affairs. 

Report of the Secretary-Treasurer 344 

Minutes of the Twelfth Annual Meeting 346 

Report of the Committee on Varietal Nomenclature 349 

Report of the Committee on Standardization of Field Experiments. . . . 350 

Report of the Editor 352 

Index 353 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. January, 1919. No. i 

A PRELIMINARY STUDY OF THE INFLUENCE OF CHLORIDES 
ON THE GROWTH OF CERTAIN AGRICULTURAL PLANTS.^ 

W. E. TOTTINGHAM. 

Introduction. 

Investigations on the nutrition of higher plants early led to the 
conclusion that carbon, hydrogen, oxygen, nitrogen, sulfur, phos- 
phorus, potassium, calcium, magnesium, and iron are essential to 
their growth. Less certainty has attended our, knowledge of the role 
of sodium, siHcon, and chlorine in plant growth. Various observa- 
tions, however, seem to have led to general belief that, altho ex- 
erting beneficial effects under certain conditions, these elements are 
unessential for most plants. As none of the seed plants tested have 
been deprived of chlorine thru successive generations, it appears that 
the necessity of this element has never been adequately investigated. 
Apart from this relation, however, it is certain that some seed plants 
contain much more chlorine than others, that some can endure much 
higher chloride concentration about their roots than is possible for 
others, and that differences in the amount of this element in the soil 
are frequently accompanied by characteristic differences in growth 
and development. In view of these considerations it appears to be 

1 Botanical contribution from the Johns Hopkins University, No. 54. This 
work was done partly in the Department of Agricultural Chemistry of the 
Wisconsin Agricultural Experiment Station and partly in the Laboratory of 
Plant Physiology of the Johns Hopkins University. The writer is indebted to 
Professors E. B, Hart and B. E. Livingston, of these respective institutions, 
for facilities and advice extended to him in the course of these investigations. 
Professor Livingston has also aided greatly in the preparation of this paper. 

Received for publication June i, 1918. 

I 



2 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

important to investigate rather fully the effects of chlorides in^nutrient 
media and to reconsider their relative importance in fertilizer practice. 

The literature of this subject presents considerable evidence that 
beneficial effects upon plant growth may be expected to follow the 
application of chlorine to the soil in the form of sodium chloride, or 
common salt. For example, Griffiths (21, p. 250-256) ^ refers to the 
use of salt as a fertilizer from ancient times, and states that about 
250,000 tons of the substance are used annually in the United King- 
dom for agricultural purposes. Hall (22, p. 334, 357) mentions the 
English practice of top dressing mangolds, potatoes, and barley with 
salt. In the last instance, this was done for the purpose of stiffening 
the straw. He ascribes the benefits of this practice to liberation of 
potassium from feldspars. Cameron (12, p. 108) says: "In spite of 
the fact that it does not contain a conventional plant food, sodium 
chloride appears to produce results quite similar to those produced by 
the usual fertilizer salts. Its use has been followed generally by an 
increased yield of crop, but occasionally by a decreased one, and it 
appears not improbable that further investigation would show sodium 
chloride to have a considerable value as a fertilizer." Other authori- 
ties express different opinions. Thus, Hilgard (29, p. 76) regards 
the usefulness of common salt in fertilizers as entirely subordinate, 
and Wheeler (75, p. 246-249, 334, 357) treats chlorine as unessential 
for plants. These writers consider o.io to 0.25 percent of NaCl in 
the soil as sufficient to inhibit the growth of cultivated plants, the 
effect depending upon the dryness of the soil. 

The available evidence regarding the effects of chlorides upon 
plant growth would seem to justify further investigation. For sev- 
eral years the writer has been interested in this problem, and the pres- 
ent paper is a report of the results already obtained. 

I. Review of Previous Experimentation. 

IS CHLORINE ESSENTIAL? 

Early in the development of the water-culture method in the study 
of plant nutrition certain investigators obtained results which led 
them to consider chlorine essential for the complete development of 
the buckwheat plant. The chief investigation in this field is that of 
Nobbe and Siegert (48), who observed peculiar physiological dis- 
turbances in buckwheat plants grown in chlorine- free nutrient solu- 
tions. The apparent need for chlorine first became noticeable at the 
fruiting stage, when it appeared that KCl and CaCl2 were superior to 
NaCl and MgCl2 as sources of this element. Certain phenomena of 

2 References are to " Literature cited," p. 28. 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 3 



growth observed in these experiments led to the conclusion that chlo- 
rine functions in the translocation of carbohydrates. Wagner (74) 
and Aschoff (2), employing somewhat different nutrient solutions 
and methods of culture, arrived at directly opposed conclusions re- 
garding the necessity of chlorine for the growth of maize ; and in the 
hands of Beyer (4), peas produced seed, but oats failed to do so, 
when grown in a chlorine-free nutrient solution. The results of these 
early investigations were decidedly conflicting and they can scarcely 
be expected to have approached finality, having been conducted when 
the problem of the physiological balancing of salts in nutrient solutions 
was as yet hardly appreciated. 

In the Laboratory of Plant Physiology of the Johns Hopkins Uni- 
versity^ buckwheat has been reared repeatedly to the production of 
apparently perfect seeds, employing as a nutrient medium the three- 
salt solution of Shive (57). These results are in agreement with 
those of Shulov (59), who found chlorine unessential for buckwheat. 
Furthermore, from the results of extensive series of water and sand 
cultures, Prianishnikov (52) concludes that "the generally accepted 
opinion of the usefulness of chlorine as such for plant life is not 
corroborated." 

From the preceding brief review it appears that chlorine, aside 
from the small content of the seed, is unessential for the complete de- 
velopment of buckwheat, and probably also for others of the com- 
mon seed plants. 

STIMULATING EFFECTS OF CHLORIDES. 

As regards the germinating stage of growth, it should be noted that 
Jarius (33) observed stimulation of several species of seeds by soak- 
ing in 0.4 percent solution of NaCl, while other salts tested were not 
so effective. Plate (51) has reported that the stimulating effects of 
certain chlorides upon the root and sprout growth of oats during 
germination were markedly different from those of the corresponding 
nitrates. The effectiveness of the chlorides in decreasing order is 
given as follows : NaCl, KCl, RbCl, LiCl, CsCl. 

As regards the complete cycle of growth, early English experiments 
with the small grains (23) gave results favorable to the use of com- 
mon salt as a fertilizer. Increases of 1.4 to 11.4 bushels of grain per 
imperial acre followed the application of salt at rates of 300 pounds 
or more, and in some cases the weight of grain per bushel and yield 
of straw were increased also. On the other hand, results obtained by 

3 Incident to investigations of Earl S. Johnston. The Johns Hopkins Uni- 
versity Circular, March, 1917, p. 211-217. 



4 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Sir John Lawes (39) led him to oppose this practice. To one of two 
plots which had been continuously cropped with wheat since 1843 he 
added salt at the rate of 300 pounds per acre per year, from 185 1 to 
1853, in addition to the common dressing of mixed minerals and am- 
monium salts added to the two plots. There was no appreciable 
variation in the yields from the two plots, either during this period or 
in the succeeding ten years. In cooperative field tests of common salt 
at the rate of 300 pounds per acre Voelcker (72) obtained an in- 
creased yield of barley in one region but a decreased yield in another. 
Tests conducted by Shelton (55) in the United States led to unfa- 
vorable deductions, despite gains in yield. In one of these tests an 
application of 300 pounds of salt increased the yield of wheat 4 
bushels per acre and produced a persistent brightness of the straw. 
Brooks and Thomson (8) applied 250 and 400 pounds of chloride of 
potassium in comparison with equal amounts of the sulfate, as con- 
stituents of a complete fertilizer, and found the two equally effective 
with grains and grasses, but clover was injured by the chloride. 

It seems to have been a rather general practice in Great Britain to 
top-dress grassland with common salt. Investigations conducted by 
the Royal Agricultural Society (13) led, however, to adverse recom- 
mendation regarding such practice. Applications of 500 pounds of 
salt per acre to soils which were mostly clays, in various parts of Eng- 
land, produced no appreciable effect upon either the quantity or qual- 
ity of grass produced. It may be noted, however, that Voelcker 
(70) had previously obtained increased yields from the use of salt in 
similar tests. In this country Jones (35, p. 71) observed nearly 100 
percent increase in weight of mead<ow fescue (Festuca ovina) on land 
which had received salt at rates of 200, 300, 500, and 1,000 pounds 
per acre to kill hawkweed (Hieracium aurantiacum) . 

The mangold and the sugar beet, closely related genetically and 
supposed to have originally inhabited the salty sands of the seashore, 
are generally stimulated to greatly increased production by sodium 
chloride. Thus, Voelcker (68), altho he had previously failed to 
obtain an increase of the crop on a stiff, calcareous clay, applied com- 
mon salt to mangolds on a light sandy soil at rates of 100, 300, 500, 
and 700 pounds per acre, and obtained increased yields from the two 
medium applications. The maximum increase over the yield from 
untreated plots amounted to over 50 percent and was obtained from 
the 500-pound application. This investigator believed that the salt 
functioned by retarding the development of the plant. More recently 
Voelcker (73) obtained, from applications of salt up to 600 pounds 
per acre on a sandy soil, supplementary to farm manure and min- 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 5 

eral fertilizers, much greater yields of mangolds than were obtained 
where the salt was omitted. Since NaNOo was included among the 
mineral fertilizers applied, Voelcker attributed the effects of the NaCl 
specifically to its chlorine content. Lawes (39) had earlier obtained 
progressively smaller yields of mangold as he increased the applica- 
tion of salt from 500 to 1,000 pounds per acre and concluded that its 
use was unjustified, but his applications seem to have been excessive. 

Among American investigations, Lyon and Wiancko (46) found 
the use of 600 pounds of common salt per acre upon a deep, medium 
loam without effect on either the yield or the percentage of sugar of 
the sugar beet. Brooks and Thomson (6), employing the salts at 
rates of 250 and 400 pounds per acre, obtained a shghtly higher yield 
but a diminished percentage of sugar from KCl as compared with 
KoSO^ in one season, but found the two salts equally effective in 
another season. 

As to other crops, the yield of turnip has responded variably to the 
application of common salt in English trials (69). The same is true 
of the use of KCl in American experiments. Thus, at the New Jer- 
sey station (81), 160 pounds per acre of KCl in mixed fertilizers was 
less productive than an equal quantity of K2SO4, while at the Massa- 
chusetts station (9) 250 pounds of KCl produced a greater yield of 
crop than did an equal quantity of K2SO4, the salts being employed 
in a complete fertilizer ration. 

The cabbage seems to respond decidedly to the application of chlo- 
rides under certain conditions. Thus, Dyer (17), operating upon a 
light clay soil in a season when drouth occurred at the critical growth 
period of the plant, obtained practically a doubled yield by applying 
300 pounds per acre of NaCl, in addition to the usual ration of 
manure, sodium nitrate, and phosphates. Contradictory results were 
obtained by Brooks and his coworkers (7), who found KCl to give 
greater yields than K^SO^ in some cases, but smaller yields in others, 
with a tendency for the former salt to produce soft cabbage heads. 
As a result of their tests upon medium clay loam, the latter investi- 
gators state that clearly, climatic conditions have an important in- 
fluence in determining the manurial effects of these salts," and in 
hot dry seasons the differences between the chloride and sulfate are 
small on the cabbage." 

At the Massachusetts station KCl has been compared with K^SO^ 
as a source of potassium upon a variety of field and truck crops. In 
the results of three years, summarized in 1904 (10), the chloride was 
superior with late crops while the sulfate proved best for early crops. 
The investigators remark that " In soils of fair retentiveness of water 



6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

only beets were decidedly best on KCl " and " Chlorides increase the 
wateriness and tend to delay the maturing of crops." In applications 
of 250 pounds of potassium salts with bone meal (11), berries and 
garden plants did equally well on the two salts, while the soybean 
yielded poorly from the chloride. 

Tests conducted by Gonehalli (19) upon mango trees in the Prov- 
ince of Bombay, British India, gave striking results. Addition of 
common salt to the soil about the roots at the rate of 10 pounds per 
tree gave an increase of nearly 150 percent in the number of fruits 
produced the following year, as compared with the yield from un- 
treated trees. The same writer reports marked increases in the yields 
of cocoanuts and rice from applications of salt. 

Probably the common potato has received more attention than any 
other crop relative to its response to the application of chlorides, es- 
pecially in comparisons of KCl with K2SO4 as a source of potassium. 
As regards the numerous experiments on this question in the United 
States, the published descriptions of the tests are often so meager as 
to make conclusions uncertain. This is especially true of those cases 
in which the method of determining starch is not given, for, as will 
appear in part 2 of this paper, the use of specific gravity values for 
this purpose is unreliable. 

In an early trial of common salt upon various Enghsh farms (71) 
at the rate of 400 pounds per acre, both alone and as part of a com- 
plete fertilizer ration, the treatment either resulted in toxicity to the 
potato or produced no effect. Equal yields of tubers having the same 
percentage of starch were obtained by Pfeiffer and others (49) 
from the use of KCl and K2SO4. About 200 pounds of each salt per 
acre were applied, in a complete fertilizer with lime, to two varieties 
of potato in confined portions of an unproductive sandy soil. The 
use of MgClo, however, in conjunction with K2SO4, seriously de- 
pressed the yield of tubers and and somewhat decreased their starch 
content. Favorable effects upon yield from the use of 600 pounds 
of KCl per acre led Emery (18) to the extreme statement that 
" K2SO4 is not desirable for the potato when KCl is obtainable." 

Investigations of these two salts with two varieties of potato and 
two types of soil in New Jersey (80) resulted in a greater yield with 
KCl, altho the tubers were more watery and of poorer quality 
than those produced with K2SO4. Jenkins (34) apphed 63 to 240 
pounds per acre of either KCl or K2SO4 in a complete fertilizer ration 
on different farms. Neither salt was decidedly superior as to yield 
of tubers, but the crop v^hich received KCl contained 0.5 percent more 
water than that produced by K2SO4. In a dry season Taft (63) ob- 



TOTTIXGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. / 

tained slightly lower yields from KCl than from K2SO4, each salt 
having been applied at the rate of 320 pomids per acre in a complete 
fertilizer ration. Potassium salts at the rate of 400 pounds per acre 
were applied with acid phosphate and sodium nitrate to two varieties 
of potato and two types of soil in Vermont (31). Without sodium 
nitrate the chloride of potassium produced tubers richer in water and 
poorer in starch, as compared with those produced by the sulfate. 
This difference disappeared with the complete fertilizer ration. 

Davidson (15) added 100, 200, and 300 pounds of potassium salts 
per acre in a complete fertilizer applied to three varieties of potato, in 
Virginia. As an average of all the plots which received each salt the 
tubers produced by KCl were reported to contain 0.7 percent less dry 
matter, but 0.6 percent more starch in the dry matter, than those pro- 
duced by K0SO4. Brooks and his coworkers (79) have devoted spe- 
cial attention to the potato in tests of the relative values of muriate 
and sulfate of potash. The Beauty of Hebron variety of potato 
seems to have been chiefly employed by Brooks, who extended his in- 
vestigations to several regions and soil types. Potassium salts were 
applied at rates of 160 to 263 pounds per acre in a complete fertilizer. 
Samples of the tubers were tested for cooking qualities by various 
famihes. In a majority of cases the results from KgSO^ were superior 
to those from KCl as to yield, composition, and quality. The tubers 
produced by the former salt were drier and superior in whiteness, 
mealiness, and flavor, as compared with those produced by the 
chloride. 

TOXIC EFFECTS OF CHLORIDES. 

Loew (45) ascribes to sodium chloride, in sufficient concentration, 
a depression of photosynthetic formation of carbohydrates by leaves 
and a decrease in the percentages of sugar in the sugar beet and of 
starch in the potato. Harter's comparison (26) of his own results 
with those of other investigators, relative to the growth of seedlings 
in salt solutions, indicates that lupine and maize are injured at lower 
concentrations of NaCl than is wheat. In Harter's investigations 
this salt was not toxic to wheat below a concentration of about 300 
parts per milHon in the solution. 

Takeuchi and Ito (64) found calcium and magnesium chlorides in- 
jurious to the rice plant when o.i percent of each was applied to a rich 
loam in pot cultures, but 0.05 percent was not particularly injurious. 

Applying various sodium salts to a sandy soil in pot culture, sup- 
plementary to a complete fertilizer containing KgCOg, Suchting (62) 
observed a depression in the yield of potato tubers and also in the 



8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

percentage of starch in these organs from the use of NaCl. The ap- 
pHcation of NaCl amounted to 580 pounds per acre foot (4,000,000 
pounds) of soil. Altho it was found that chlorine migrated into the 
tubers, there was no apparent correlation between such migration and 
the extent of injury observed. 

At the Rhode Island station (76), the chlorides of calcium, mag- 
nesium, and ammonium were added to completely fertilized soil in 
large pots. With a soil of acid reaction, calcium and ammonium chlo- 
rides were decidedly toxic to cereal grains and to the potato, but mag- 
nesium chloride was not injurious in the concentration tested. The 
toxicity of the former salts was overcome by liming. It was con- 
cluded from these results that all of the apparently conflicting evi- 
dence regarding poisonous actions of chlorides upon plants, when 
these salts are applied in moderate quantities, might be harmonized 
upon the basis of differences in the chemical reaction of the soil. 

In extensive investigations on the effects of chlorides in alkali soils, 
Harris (25) has found sodium chloride, at 0.2 percent concentration 
in the soil, to reduce the germination of wheat by half. He finds this 
to 'be the most toxic of the several common chlorides investigated. 
Harris found the toxic efifect of chlorides to be only half as great in 
sand as in loam, the effect in dry soil being less than in wet. The 
limit to productiveness of the soil is set by this investigator at 0.3 
percent of chlorides in loam and 0.2 percent in coarse sand. 

SPECIAL PHYSIOLOGICAL RESPONSES TO CHLORIDES. 

The responses of plants to the presence of chlorides in the nutrient 
medium may be divided into two apparently distinct classes, namely, 
those which affect the form of the plant (morphological) and those 
which influence its composition (compositional). 

Marked changes in structure and transpiring power of plants under 
the influence of sodium chloride have been observed by Harter (27) 
with wheat. Employing a saline soil in which NaCl formed about 70 
percent of the total salts, he diluted this with garden loam, so as to 
obtain soils containing 1.4, i.o and 0.7 percent of NaCl, on the basis 
of dry weight. Tumbler cultures of these soils were sealed with par- 
affin to permit comparative transpirational measurements by weigh- 
ing. In general, the epidermal cells of the plants in the saline soils 
were smaller than those of the control plants grown in the loam soil, 
and the cuticle was thicker in the former case, the leaf surface de- 
veloping a conspicuous amount of bloom. Leaves from cultures so 
modified lost but one-third to half as much water, relative to dry 
weight, as did leaves from the control culture. On the other hand, 



TOTTIXGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 9 

leaves from cultures in which the saline content of the soil was in- 
sufficient to affect the amount of bloom on the leaves showed lo to 
20 percent higher transpiration rate per unit of leaf area than similar 
leaves from the control plants. 

As to the exterior form of the plant, Hansteen (24, p. 318) ob- 
served, with water cultures, that solutions containing chlorides, as 
compared with other salts, produced wheat plants with longer roots 
and shorter leaves. He considered this condition to be a response to 
a decrease in the rate of water absorption, both brought about by an 
increased absorption of the chlorine ion. 

The chemical composition of the plant, as this may be influenced by 
the addition of chlorides to the soil, seems to have been investigated 
but little, save in the case of the sugar beet and potato. Some of these 
effects have been pointed out already (Brooks and Thomson, 6, 10; 
Pfeiffer cf al., 49; Hills, White, and Jones, 31 ; Davidson, 15 ; Brooks, 
79: Suchting, 62). According to Bolin (5) NaCl and KCl appHed 
with the usual fertilizers in Sweden, while increasing the total crop, 
appeared to increase the wateriness of the sugar beet and potato. De 
Ruijter de Wildt and his coworkers (16) found an application of 267 
pounds of common salt per acre without effect upon the percentage of 
sugar in the sugar beet, but an excessive salt content of the soil (due 
to flooding with sea water) depressed the sugar content. They also 
note some disturbances in the distribution of nitrogen compounds. 

2. Experimentation, 
general considerations. 

The plan of the work here described comprehended both qualita- 
tive and quantitative investigation of the responses of various agri- 
cultural plants to the application of chlorides in various nutrient 
media. As culture media the well-known nutrient solution of Knop 
(37) and also common soil were employed in the greenhouse, and 
certain experiments were conducted upon field plots. As indicated 
by the preceding review of previous experimentation, the effects of 
substances added to the soil in field experiments are liable to obscure- 
ment by uncontrolled climatic factors, as well as by soil peculiarities. 
Indeed, one of the prime desiderata of future experimentation in 
plant nutrition is the development of apparatus for the control of the 
chief climatic factors, to supplement the more refined methods of con- 
trol now developed with artificial nutrient media. 

The chlorides of potassium and sodium were chiefly used as sources 
of chlorine. Either the sulfate or nitrate of potassium, depending 



lO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

upon the formula of nutrients employed, was replaced partly or wholly 
by potassium chloride, and sodium chloride was applied either alone 
or supplementary to a complete nutrient mixture. 

The plants grown were chosen with a view both to their agri- 
cultural importance and to the including of a considerable range of 
genera, with supposedly different physiological requirements. Per- 
haps the most convenient descriptive treatment of the experimentation 
may be based upon the species of plants used, and the discussion to 
follow will conform to this plan. Results from prehminary cultures 
led to emphasis being placed upon the so-called root crops. These 
preliminary cultures were conducted with Knop's solution and Tot- 
tingham's (65) modification of the same, found somewhat better for 
the growth of young wheat plants. Inasmuch as the usual amount of 
MgS04 was replaced either wholly or in part by MgClg and 
Mg(N03)2 in these cultures, they must be considered as more or less 
deficient in an important nutrient element, namely, sulfur. Wheat, 
garden peas, and red clover were brought to a stage of apparent vege- 
tative maturity in the various solutions employed, altho only the 
peas produced seed and neither of the other plants blossomed, even 
in the complete nutrient solution. Suffice it to state that the MgCU 
was very toxic to the clover, but not to the other plants, as evidenced 
by the yields of dry matter. The remarkable fact about these cultures 
was that the maximum application of chloride led to a greatly in- 
creased length of roots. This increase ranged from 120 percent in 
the case of peas to 180 percent in the case of clover. Some corre- 
sponding increase in production of dry matter of the roots accom- 
panied the greater elongation of these organs. That the elongation 
was due in part to the removal of a suppressing effect of MgSO^ is 
evidenced by the fact that substitution of Mg(N03)2 for the latter 
gave increased developments of roots, but the effects were not so 
pronounced as those produced by the chloride. In view of these re- 
sults it appeared advisable to devote special attention to those plants 
in which the root comprised the major portion. 

WHEAT. 

Thus far, wheat (Triticum sativum) has been studied by the 
writer only in water culture, employing as a basis Knop's solution 
having a total salt concentration of 0.2 percent (osmotic value about 
0.9 atm.) with KHgPO^ as the source of phosphorus. Uniform 
seedlings of the Fulcaster variety obtained by Shive's method (58, p. 
343) were mounted by the method of the writer (65, p. 173-175) 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. I I 

cylindrical glass jars of approximately 4^5 c.c. capacity (pint jars of 
the Mason pattern), each jar being covered with heavy brown paper 
to exclude light. The chlorine ion was introduced by replacing the 
KNO3 of Knop's solution partially or completely with KCl, by adding 
NaCl to the unmodified solution, or by replacing the KNO3 wholly 
with KCl and adding NaNO.5, molecularly equivalent concentrations 
of these various salts being employed.* 

Six different solutions were employed (see the column headings of 
Table i), four cultures of each, each culture having three seedlings. 
During the growth of this culture series (February 16 to March 24, 
1917, at Baltimore) the cultures stood on a rotating table of the type 
used by Shive (58, p. 344, 345), to equalize the aerial environment for 
all cultures of the series. The nutrient solutions were renewed after 
intervals of three days. At the end of the growth period the roots 
were washed and their approximate maximal lengths were measured. 
They were then severed from the tops and both roots and tops were 
weighed after drying at about 105° C. The volume of solutions 
absorbed by the plants during the last eight days of growth were 
also measured in this series. 

As partial indices to the climatic conditions attending growth, 
temperature records were obtained by a thermograph placed in shade 
beside the rotating table, and the evaporating power of the air was 
determined by means of a white spherical porous-cup atmometer (43), 
the readings being reduced to those of the Livingston spherical 
standard. The average daily maximum temperature was 29.3° C, 
the average daily minimum was 16.9°, and the extremes for the period 
were 31° and 10.5°. The total corrected loss from the atmometer for 
the culture period was 648.6 c.c. 

Data of yield, root length, and water absorption appear in Table i. 
From the data in this table it appears that increasing amounts of 
KCl depressed slightly the yields of dry tops and roots, as well as 
the length of roots. On the other hand, while the additions of NaCl 
and NaN03 seem to have depressed the length of roots equally, both 
led to slightly increased yields of dry matter as compared with the 
other solutions. The maximal application of KCl and the use of 
NaCl were attended by increased water absorption in proportion to 
the dry tops, but these increases were not so great as that produced 
where NaN03 was supplied, relative to the dry tops of the plants. 

^ As here used the unmodified Knop's solution had the following volume- 
molecular partial concentrations of the respective salts: Ca(N03)2, 0.0069; 
MgS04, 0.0025; KH2PO4, 0.0017; and KNO3, 0.0029. Four or five drops of a 
dense suspension of FePOi were added. 



12 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The slight effects of chlorides upon this plant, as here shown, are in 
agreement with the extensive results of Trelease (66). 



Table i. — Effect of chlorides introduced into Knop's nutrient solution upon 
the growth of young wheat plants therein. 



Data. 


Solution I, 
unmodified 
Knop's. 


Solution 2, 

o.oi of 
KNO3 re- 
placed by 


Solution 3, 

0.1 of 
KNO3 re- 
placed by 


Solution 4. 

total KNO3 
replaced 
by KCl. 


Solution 5, 
as I with 
addition 
of NaCl. 


Solution 6, 
as 4 with 
addition 
<Jf NaNOs. 
















mg. : 














Yi m 1 1 tn 


86o 


888 




059 


097 


OUJ! 


IVT i n 1 m 1 1 tn 




693 


726 


626 


761 


742 




799 


811 


750 


744 


821 


023 






























Maximum 


232 


248 


221 


252 


256 


238 




207 


195 


204 


175 


216 


216 




220 


227 


214 


210 


239 


232 


Greatest root length, 














mm.: 
















231 


225 


238 


200 


191 


222 


Minimum 


200 


216 


200 


153 


178 


178 




215 


220 


218 


186 


185 


195 


Water absorption, c.c. : 














Average per culture 


293 


288 


286 


305 


348 


374 


Average per gram 














of dry tops 


367 


325 


380 


410 


423 


456 


Average per deci- 














gram of dry roots 


133 


116 


134 


145 


145 


162 



BUCKWHEAT. 

The methods of culture applied to buckwheat {Polygonum fago- 
pyrum) were those just described in connection with wheat, except 
that when the cultures were discontinued the leaves were severed at 
their junctions with the petioles and dried separately. This added 
procedure made possible a direct comparison of the rates of water 
absorption (as approximately measuring the transpiration ratio) with 
the dry weights of leaves. During the period of growth of these 
cultures (December 7, 1916, to February 6, 1917, at Baltimore), the 
climatic data obtained were as follows : Average maximum daily 
temperature 24.2° C, average daily minimum 15.2°, and extreme 
range from 30° to 8°. The corrected total evaporation for the period 
was 612.6 c.c, from the white spherical atmometer. 

The data of this culture series appear in Table 2. Seed produc- 
tion is there expressed by an arbitrary method ; o denotes that flowers 
only were produced; i denotes apparently immature seeds; and 2 
denotes apparently mature seeds. From these relative scores an 
average value is shown for each nutrient solution. 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTLI. I 3 



Table 2. — Effects of chlorides introduced into Knop's nutrient solution upon 
buckwheat grown to maturity therein. 



Data. 


Solution I, 
unmodified 
Knop's. 


Solution 2, 

o.oi of 
KNO3 re- 
placed by 
KCl. 


Solution 3, 
o.i of KNO3 
replaced 
by KCl. 


Solution 4 , 
total KNO3 
replaced 
by KCl. 


Solution 5, 
as I with 
addition of 
NaCl. 


^ : 

Solution 6, 
as 4 with 

addition of 
NaNOa. 


Dry weight of leaves, 














mg.: 
















1.293 


1.454 


I.319 


1,096 


1.079 


1,168 




878 


911 


972 


807 


557 


646 


Average 


1,128 


1,063 


1,124 


956 


841 


937 


Dry weight of stems, 














mg.: 














Maximum 


1.332 


1.552 


1,419 


1,480 


1.253 


1.307 


Minimum 


1,091 


1,022 


1. 151 


955 


525 


771 


Average 


1,181 


1,199 


1.273 


1,135 


936 


1,101 


Dry weight of roots, 














mg.: 














Maximum 


194 


171 


216 


164 


180 


142 


Minimum 


117 


135 


139 


118 


46 


88 


Average 


154 


154 


173 


131 


119 


114 


Greatest root length, 














mm. : 














Maximum 


241 


230 


235 


266 


223 


282 




190 


177 


196 


137 


142 


150 




214 


211 


216 


192 


179 


192 


Average water ab- 














sorption, c.c. : 














Per culture 


248 


225 


238 


210 


160 


200 


Per gram of dry leaf 


220 


212 


212 


220 


190 


214 


Per decigram of dry 














root 


161 


146 


138 


160 


135 


176 


Seed production score 


1.2 


1.2 


I.O 


.8 


1.0 


1.0 



From Table 2 it is evident that the maximal applications of chlorine 
depressed the production of dry matter in leaves and roots in all cases. 
The dry weight of the leaf tissue was decidedly lowest where NaCl 
was present in the solution, and this particular solution also produced 
the least dry matter of stem and petiole, but root length was quite 
uniformly depressed in all cultures that received the maximal amount 
of chlorine. No significant differences in seed production were 
apparent. 

With the exception of the culture which received NaCl the amount 
of water absorption per unit of dry matter in the leaves was quite 
constant. This particular salt seems to have caused a specific reduc- 
tion in transpiration. The ratio of water absorption to dry weight 
of roots varied irregularly, but root length and water absorption per 
culture varied in a corresponding manner, greater absorption accom- 
panying longer roots. 

From these considerations it appears that the chlorine ion in these 
cultures produced disturbances evident as decreased root length, de- 



14 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

creased production of dry matter of leaves and roots, and decreased 
water absorption per culture. In some of these ways sodium chloride 
appears to have produced specific effects, such effects being least 
production of dry matter in both leaves and stems and the only varia- 
tion from uniformity in the ratio of water absorption to foliar dry 
matter. 

On the basis of the theory of electrolytic dissociation (47, bk. 2, 
chap. 7), according to which the salts as here employed should be 
almost completely dissociated into their constituent ions, it seems 
difficult to conceive appreciable chemical or physical differences be- 
tween the culture solutions of formulas 5 and 6, Table 2. Neverthe- 
less, the buckwheat plants exhibited in solution 5, to which sodium 
chloride was added, a response markedly different from that observed 
in solution 6, which received the same amounts of sodium and chlorine 
(but supplied in different salts) as did the former solution. In view 
of the current chemical interest in the relative roles of molecules and 
ions in reactions (i), the apparently specific effects of the sodium 
chloride molecule here observed surely merit further investigation. 

RADISH. 

A single series of soil cultures was conducted in the greenhouse at 
Madison with a small, round variety of radish (Ra^phanus sativus) 
designated as Earliest Scarlet Turnip. Miami silt loam was em- 
ployed in cylindrical stoneware jars 12 cm. deep and 18 cm. in diameter 
(of I gal. U. S. capacity), capable of holding 5 kg. of air-dried soil. 
The latter was secured to a depth of 3 to 4 inches from the University 
of Wisconsin farm, and was passed through a wire screen having 
meshes 6 mm. square. It then contained about 15 percent of mois- 
ture, and analysis by the standard methods (78) showed it to have 
the following partial composition, upon the oven-dried basis : Total 
nitrogen, 0.15 percent; total phosphorus, 0.06 percent; total potas- 
sium, 1.83 percent; CaCOg, 0.33 percent; humus, 1.38 percent. 

The plan of fertilizing included both the substitution of KCl for 
K2SO4 in a complete fertilizer mixture and the supplementary addi- 
tion of NaCl, chemically equivalent amounts of these salts being 
employed. Of the several salts the following amounts were employed 
per jar: 2.0 gm. CaHP04-2H20, 2.05 gm. K2SO4, 1.76 gm. KCl, and 
1.38 gm. NaCl. Two grams NaNO. was also added in dissolved por- 
tions as the plants developed. This rate of application has ibeen found 
about 70 percent optimal for these proportions of salts in the growth 



TOTTIXGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. I 5 



of rape under similar cultural conditions. A glass tube 2 cm. in 
diameter and about 13 cm. long, fixed upright in the soil, provided for 
aeration and subsurface watering. By daily weighings, the moisture 
content of the soil was kept at about 50 percent of saturation, as 
determined by Hilgard's method (29, p. 208, 209), or at about 25 
percent on the basis of the weight of the dry soil. Distilled water 
was used. Eight plants per jar were grown to the first phase of 
maturity (February 24 to April 1.9, 1915), as indicated by the death 
of the basal leaves. 



Table 3. — Effects of chlorides introduced into the fertiliser treatment of radish, 
carrot, and parsnip grown from loam soil in the greenhouse. 



Data. 


Complete, K as K2SO4. 


Complete, K as KCl. 


Complete, K as K2SO4, 
plus NaCI. 


No. I. 1 No. 2. 


Aver- 
age. 


No. 3. 


No 4. 


Aver- 
age, 


No. 5. 


No. 6. 


Aver- 
age. 


X icivi \ji cxii 1 y 

tops, gm.: 

Radish 

Carrot 

Parsnip 

Yield of oven-dry 

roots, gm. : 

Radish 

Carrot 

Parsnip 

Dry matter in fresh 

roots, percent: 
Radish 


8.4 
10.3 
25-7 

9.4 

9-3 
44.2 


9.1 
9.9 
23.6 

9-3 
11.6 
38.0 


8.8 

lO.I 

24.7 

9.4 

10.5 
41. 1 

5.8 
11.8 
23-7 

16.4 
17-3 
5.8 

4.1 
19.1 
86.2 


10.3 
II. 7 
26.3 

9.6 
14.1 
35-0 


9.9 
14.0 
23-3 

9.1 
12.2 
37-3 


lO.I 
12.9 
24.8 

9.4 
13-2 

36.2 

5.9 

II.6 
21.0 

13-4 
19.6 
3.7 

3.7 
19.7 
22.6 


10.2 
II. 2 
21.9 

10.4 
13-6 

25-9 


10.4 

20.5 

10. 

13.6 
28.7 


10.3 
II.4 
21.2 

10.2 
13.6 
27.3 

5-4 
11.4 
21.5 

13.3 
18.9 
3.0 

7.5 
22.5 
22.5 


Carrot 














Parsnip 














Sugars in dry roots, 
percent : 
Glucose: 

Radish 














Carrot 




























Sucrose : 

Radish 














Carrot 














Parsnip 

























Determinations were made of the sugar contents of the radish 
roots. In attempting to extract the sugars from the dried, powdered 
roots of the sugar beet it had been found that the hot alcoholic ex- 
traction applied by Stone (6i, p. 12) to cereal grains gave incomplete 
results, even when several times repeated. A modified method was 
therefore adopted. The dried and powdered roots were first ex- 
tracted with water, then the aqueous extract was evaporated nearly 
to dryness and the sugars were removed by subsequent extraction 



I6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

with alcohol of about 90 percent strength, as diluted by the aqueous 
residue. After removal of the alcohol and the preparation of the 
aqueous solution of the sugars the reducing power of the latter, before 
and after inversion with HCl, was determined, following the Defren- 
O'Sullivan method (56, p. 74-76). The reducing sugar and invert 
sugar contents, computed from the reducing power (56, Table 7) 
probably represent chiefly glucose and sucrose respectively, and they 
are so designated in the present report. 

The results of these tests with radish are given in Table 3, which 
also presents the corresponding results for carrot and parsnip, to be 
referred to later. The application of the chlorides seems to have 
increase'd the yield of aid-dried leaves of the radish, while only NaCl 
thus affected the dry matter of the root. The chloride led also to the 
production of a more watery root. As regards the percentage of 
sugars in the dry matter of the root, both chlorides somewhat de- 
pressed glucose, while NaCl led to an increase of sucrose. 

CARROT. 

A short-rooted variety of carrot (Daucus carota) of unknown name 
was grown to apparent maturity (May 10 to July 6, 191 5, at Madison) 
in the pots of soil which had produced the radish roots just described, 
each pot supporting seven plants. The original fertilizer application 
was repeated, but the moisture of the soil was maintained at only 40 
percent of saturation. The data of yields and analyses appear in 
Table 3. 

It is apparent that both chlorides stimulated the production of dry 
matter in the roots of this plant and, to a less degree, in the tops. 
The percentage of dry matter in the roots was but slightly reduced 
by the application of chlorides. While the percentage of glucose 
was increased by both chlorides, only NaCl enhanced the production 
of sucrose. 

PARSNIP. 

In view of the genetic relationship of the parsnip (Pastinaca sativa) 
to the carrot it was considered of interest to test its response to 
chlorides. The cultures were conducted in boxes of cypress wood, 
30 cm. long, 12.5 cm. wide, and 25 cm. deep, conveniently holding 
15 kg. of silt loam. Fertilizers were applied as for radish and carrot, 
but the water supply was not controlled by weighing. A short, round 
variety of parsnip was employed (January 6 to June 10, 1916, at 
Madison), three plants in each culture. The data appear in Table 3. 



TOTTIXGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 1/ 



Toxic effects of the chlorides were pronounced with this crop as 
regards the yield of roots, but the growth of tops suffered only from 
NaCl. Both chlorides produced more watery roots than did the 
chlorine-free ration. It appears significant of specific disturbing 
eft'ects upon metabolism that these more watery roots were decidedly 
deficient in glucose and seriously depressed in sucrose, as percentages 
of the dry matter. In these respects the results for parsnip contrast 
sharply with those for carrot. 

SUGAR BEET. 

Greenhouse Tests. — The Vilmorin's Improved variety of sugar 
beet (Beta vulgaris) was grown, at the rate of three plants to the 
culture, in the deep wooden boxes previously described. Series i re- 
ceived salts at half the rates specified for the parsnip. In this series 
NaCl was applied alone, but not supplementary to a complete fertil- 
izer. Series 2 received the fertilizer ration specified for the parsnip. 
Its growth period extended from January 6 to June 16, 1915, while 
that of series i extended from October 29, 1915, to May 23, 1916, 
both at Madison. The data for both series appear in Table 4. 

Table 4. — Effects of chlorides introduced into the fertilizer treatment of the 
sugar beet grown upon loam in the greenhouse. 



Description of fertilizer. 





Yield of 
air-dry 
tops. 


Yield of 
oven-dry 
roots. 


Dry matter 
in fresh 
roots. 


Sugar in dry roots. 


Culture No. 


Glucose. 


Sucrose. 




Ser. 
I. 


Ser. 
2. 


Ser. 


Ser. 
2. 


Ser. 


Ser. 
2. 


Ser. 


Ser. 
2. 


Ser. 
I. 


Ser. 
2. 


I 


Gm. 
20.0 


Gm. 


Gm. 
52.4 
42.3 
47.4 
44-7 
57-2 
51.0 
62.6 


Gm. 


Gm. 


Gm. 


Pet. 


Pet. 


Pet. 


Pet. 


2 


16.S 
18.3 

16.9 
19.9 
18.4 
27.2 
28.7 
28.0 
32.7 
38.9 
35.8 


















Average 
3 






18.5 




2.8 




61.3 




4 


















Average 
5 


30.5 
38.6 
34.6 
43-7 
41-3 
42.5 
46.6 
45-7 
46.1 


34-2 
44.1 

39-2 

61.4 
56.0 
58.7 

61.3 


17.7 




3.3 




60.3 




6 


47.3 
55.0 
82.4 
76.0 
79.2 














Average 
7 


16.3 


25.6 2.8 


2.3 


60.2 


77.0 


8 










Average 
9 


16.8 


23.8 


4-4 


2.7 


57.0 


74-3 


10 






52.3 
56.8 




1 

....[.... 








Average 




:::: 




24.0 .... 


3.3 




60.7 



No fertilizer 

Do 

Do 

NaCl onlj- 

Do 

Do 

Complete, K as K2SO4 

Do 

Do 

Complete, K as KCI . . 

Do 

Do 

As 5 and 6, plus NaCl 

Do 

Do 



The data for sugar beet show generally the same departures as 
those for carrot where chlorides were applied, namely, marked in- 
crease in yield of dry matter of roots and smaller increase in yield 



1 8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

of tops, increased percentage of water in the fresh roots, and in- 
creased percentage of glucose in the dry roots. The sucrose content, 
on the other hand, was somewhat depressed by the chlorides, altho 
the increased production of root more than compensated the slight 
reductions of sucrose in these roots. 

Field Cultures. — ^The field tests of sugar beet were conducted 
with the application of common salt alone. The soil was Miami silt 
loam, previously referred to, which had received liberal applications 
of farm manure. Rectangular plots of one-eightieth acre (1X2 
rods) were laid out upon a level area of a field planted to Lane's 
Improved variety of sugar beet, at Madison. Fine salt was applied 
broadcast at rates of 260 and 520 pounds per acre upon separate plots 
either in one application, 12 days after planting, or in two equal ap- 
plications, 12 and 31 days after planting. The number of plants was 
reduced to no per plot 40 days after planting, this being the least 
numher on any plot at the time. After recording the total weight of 
the freshly harvested roots, six beets were dried for analysis. The 
data on yields and composition appear in Table 5. 



Table 5. — Effects of adding NaCl to field cultures of sugar beet on loam soil 
fertilised with farm manure. 



Plot 
No. 


NaCl added. 


Yield of fresh 
roots. 


Sugars in 
Glucose. 


dry roots. 
Sucrose. 








Kilograms. 


Percent. 


Percent. 


I 






90.0 


1.7 


65.0 


2 


1,590 gr. 


(2 applications) 


115. 


4.4 


61.2 


3 


795 gr. 


(do.) 


103.6 


4.1 


71.2 


4 


1,590 gr. 




96.7 


2.8 


54-7 


5 


795 gr. 


(do.) 


101.3 


3-3 


53.8 


6 






92.2 


2.8 


57-2 



It will be seen from the data in Table 5 that the number of applica- 
tions influenced the yield. Thus, although the higher amount of salt 
produced the least efifect when applied as one dressing, it led to the 
highest yields when distributed between two applications. In a gen- 
eral way, the percentages of glucose increased with the yield of roots, 
but the percentage of sucrose was depressed by the salt in most cases, 
and particularly by the single applications. While this limited pre- 
liminary test gives httle basis for conclusions it appears to justify 
more extended investigation of the problem involved. 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 1 9 



POTATO. 

Greenhouse Tests. — Greenhouse cultures of potato (Solanum 
tuberosum) were conducted at Madison in cubical boxes of cypress 
wood I foot deep, containing 20 kg. of Miami silt loam. In the com- 
pletely fertilized cultures the following kinds and amounts of salts 
were added per box : NaNOo, 2.44 gm. ; CaHP04-2H20, 2 gm. ; and 
either K^SO^, 3.2 gm., or KCl, 2.74 gm. These amounts of the potas- 
sium salts are chemically equivalent. In some cultures KCl replaced 
one-fourth, one-half, or three-fourths of the K0SO4 of the complete 
ration, and in other cases KoSO^ and KCl were applied alone at the 
maximum rate of the complete ration. NaCl was similarly employed, 
as is indicated in Table 6. One of each pair of duplicate cultures, 
of the Triumph variety, received 8 gm. of CaCOo. As already inti- 
mated, the rations were so manipulated that the various applications 
of potassium salts supplied the same amount of potassium, and the 
same was true of the chlorine supplied by the chlorides. 

One plant per culture was grown from a cubical cutting about 2.5 
cm. thick. Distilled water was supplied as the appearance of the 
soil indicated need, and each series was harvested as soon as all 
the tops appeared mature. All tubers less than half an inch in 
diameter were discarded and the remainder were sliced and dried 
3-t 55° C. Starch determinations were then made by the standard 
method of the American agricultural chemists (78, p. 53.)^ Filtered 
saliva was employed as the hydrolizing agent, and the glucose finally 
produced was determined in the manner already described. No cor- 
rection was made for the small amount of reducing sugars probably 
present in the tubers. 

In Table 6 the average data for duplicate cultures are given 
thruout, as liming was found to produce no specific effects upon either 
yield or composition of the tubers. In series i, the Triumph variety 
was grown, and tubers from this series were employed as seed for 
series 2. Series 3 was grown in a sandy soil from Spooner, Wis., 
but in all other cases Miami silt loam was employed. Series 4 was 
conducted with the Rural New Yorker variety. 

While the limited data of Table 6 do not justify conclusive state- 
ments they indicate superiority of KCl over K2SO4 in the complete 
fertilizer, relative to percentage and total yield of dry matter in the 
tubers. As regards percentage of starch the Triumph variety was in- 

5 Comparative trials had shown the measurement of starch by specific gravity 
of the tubers fo be unreliable, '^his result is confirmed by Watson (Va. Agr. 
Expt. Sta. Bui. 55, 1905) and by Morrison (unpublished thesis for degree of 
B.Sc, Univ. of Wis., 1911.) 



20 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



different to KCl, while the Rural New Yorker was depressed thereby, 
in the completely fertilized cultures. Judged by all three of the cri- 
teria employed, both potassium salts were detrimental when applied 
alone to the late variety of potato, but KCl the more so, as compared 
with the unfertilized cultures. It does not appear that NaCl was par- 
ticularly injurious to the Triumph variety, excepting the production 
of more watery tubers, as compared with the unfertilized controls. 
In the latter respect, however, its results fall short of those of the 
complete fertilizer. Evidently the variety of potato is a more deter- 
minate factor than the type of soil in the effects of chlorides observed 
under these conditions. 



Table 6. — Effects of chlorides upon the yield and composition of potato tubers 
grown in soil cultures in the greenhouse. 



Data. 



No 
ferti- 
lizer. 



Complete. 



All 
potas- 
sium as 
K2SO4. 



0.75 of 
potas- 
sium as 
K2SO4, 
0.25 as 
KCl. 



0,50 of 
potas- 
sium as 
K2SO4, 
0.50 as 
KCl. 



0.25 of 
potas- 
sium as 
K2SO4, 
0.75 as 
KCl. 



All 
potas- 
sium as 
KCl. 



K2SO4 
only. 



KCl 
only. 



Number of tubers 
per culture: 

Series i 

Series 2 

Series 3 

Series 4 

Yield of air-dry 
tubers, gm.: 

Series i 

Series 2* 

Series 3 

Series 4 

Air-dry matter in 
fresh tubers, 
percent : 

Series i 

Series 3 

Series 4 

Starch in dry mat- 
ter, percent: 

Series i 

Series 3 

Series 4 



5-7 
27.4 

7.5 
11.9 



24.2 

25.5 
24.6 



80.0 
75-3 
77.4 



9.0 
71.8 

8.1 
II. 7 



21.8 

15-9 
20.7 



74.0 
75.8 
78.6 



9.9 
1.2 



9.8 



20.4 



18. 1 



77.7 



II. 8 
71.8 



5.9 



21.3 



72.6 



16.9 
36.0 



1.6 



71.3 



16.5 
91.0 
6.6 

13-2 



23.7 
17.2 
22.8 



75-3 
78.3 
70.S 



9.9 



20.9 



73.2 71-7 



5-9 



18.8 



" The data for this series are for fresh tubers instead of air-dry ones. 



Field Cultures. — Field tests of chlorides upon the potato were con- 
ducted at Madison, with a basal fertilizer ration per acre of 160 pounds 
of NaNOg, 400 pounds of acid phosphate, and 200 pounds of K2SO4. 
KCl was substituted for K2SO4 by intervals of one-fourth of the full 
amount of potassium, as in the greenhouse cultures. In addition to 
an unfertilized plot, NaCl was applied alone at the rate of 136 pounds 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 21 

per acre, equivalent to the maximum application of KCl in the com- 
plete fertilizer. The plots were of the shape and size employed for 
the sugar beet, but they were laid out permanently with alleys 3 feet 
in width between adjacent plots. NaNOo was broadcasted over the 
plots in two applications as the plants developed, but the other fer- 
tiHzers were applied with the drill. Series i, Triumph variety, ma- 
tured in III days, with a severe drouth from the 38th to the io8th 
day. Series 2, Rural New Yorker variety, matured in 127 days, but 
a prolonged period of heavy rains near the close of this period caused 
excessive loss of the tubers by decay. The crop of series i was di- 
vided into marketable and unmarketable tubers, the former weighing 
65 gm". or more each. Six tubers of average size were selected from 
this lot for analysis. Only the two marginal and two middle rows of 
each plot were dug in series 2. Twelve representative tubers were 
then taken for cooking tests^ and for analysis. All of the data here 
referred to are presented in Table 7. 



Table 7. — Effects of chlorides upon the yield and composition of potato tubers 

grown on field plots. 



Description of fertilizer. 


Market- 
able 

tubers, 
series i. 


Yield of 
air-dry 
tubers, 

series i. 


Dry matter in 
fresh tubers. 


Starch in dry 
matter. 


Relative 
cooking 


score of 
quality. 


Ser. I. 


Ser. 2. 


Ser. I. 


Ser. 2. 


Boiling. 


Baking. 




Pet. 


Grams. 


Pet. 


Pet. 


Pet. 


Pet. 








45 


3.270 


19.2 


20.7 


«7i.8 


^80.1 


5 


6 


Complete, all potassium as 


















K2SO4 


49 


4,310 


18.4 


20.6 


72.3 


81.0 


3 


2 


Complete, 0.75 of potassium 


















as K2SO4, 0.25 as KCl. . . 


39 


4.470 


20.4 


20.4 






2 


3 


Complete, 0.5 of potassium 










as K2SO4, 0.5 as KCl 


44 


4.270 


18.6 


19.7 






4 


4 


Complete, 0.25 of potassium 










as K2SO4, 0.75 as KCl. . . 


48 


4.150 


I8.I 


20.4 






6 


5 


Complete, all potassium as 










KCl 


53 


4,120 


18.5 


21.0 


73-4 


79-9 


I 


I 


NaCl only 


35 


2,650 


18. 1 


20.0 


71.4 


79-7 


7 


7 



° Mother tubers contained 72.4 percent of starch. 
^ Mother tubers contained 75.7 percent of starch. 



In series i (Triumph variety) the higher amounts of KCl in the 
complete fertilizer appear to have depressed the yield of dry matter, 
while NaCl exerted this effect decidedly, as compared with the unfer- 
tihzed plot. The only significant departure from a uniform per- 
centage of marketable tubers seems to have been the decline' due to 

^ Performed by Miss Ada Hunt, of the Home Economics Department of the 
University of Wisconsin. 



22 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

NaCl. While KCl was without effect upon the percentage of dry 
matter in the tubers of either series, NaCl alone seems to have slightly 
decreased this value. No significant variations in the percentage of 
starch resulted from the varied fertilizer treatment. In cooking qual- 
ity the tubers produced by the fertilizers containing the greater pro- 
portions of K2SO4 were generally superior to those receiving more 
KCl, but those receiving potassium entirely as KCl scored first by 
both tests. There was no doubt of inferiority of the tubers produced 
with NaCl alone, these being particularly characterized by the judges 
as " of a bitter, alkaline flavor." 

While these results indicate that chlorides influence the yield of the 
potato tuber much more than they affect its composition, their chief 
value appears to lie in the results they promise for more extended in- 
vestigation along the lines indicated here. 

Succeeding field crops have apparently benefited from the chlorides 
applied to the potato crops just described. Following the Rural New 
Yorker potatoes, the plots were sown to barley (Hordeum vulgar e) 
and common red clover (Trifolium pratense). In the following year 
(1916),. the yield of barley grain on the unfertilized plot was 10.5 
pounds, while on the plots which had been completely fertilized for the 
potatoes it ranged from 12.5 to 16.0 pounds, and where NaCl had been 
applied alone it amounted to 15.0 pounds. The ratios of grain to straw 
for these respective treatments were 0.45, 0.45 to 0.52, and 0.56, 
respectively. The yield of grain and the ratio of grain to straw in- 
creased with the proportion of KCl in the rations of the completely 
fertilized plots. In the following year (1917), the yields of clover 
hay were 45 pounds for the unfertilized plot, 56 to 60 pounds for the 
completely fertilized plots, and 63 pounds for the plot which had re- 
ceived NaCl only. The yields were practically the same whether 
K2SO4 or KCl had been applied in the complete fertilizer. 

The Mechanism of Chlorine Effects, 
natural supply. 

In considering the possible use of chlorides as fertilizers it is im- 
portant to take account of the supply of chlorine in the soil. There 
is also some acquisition of this element in the rainfall, although a por- 
tion of this supply doubtless circulates within local areas of soil and 
atmosphere. 

The following chlorine-bearing minerals, soluble in water or dilute 
acids, appear to occur commonly in soils (3, p. 182 ; 50, p. 48), namely : 
Halite (NaCl), sylvite (KCl), apatite [Ca,.Ca.Cl.F(PO,)3], and 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 23 

sodalite [Na4(AlCl) Al2(Si04)3] . Few, if any, soil analyses give 
data on the total chlorine content of the soils concerned. Preliminary 
attempts to secure such data in the present study by the method 
of alkaline fusion (30, p. 184) encountered difficulties, but a number 
of determinations of water-soluble chlorine were made upon air-dried 
samples of soils pulverized to pass a sieve having 100 meshes to the 
inch. Extracts of 25 grams of soil in 400 cc. of water, obtained by 
agitation for two hours at 17° C, were filtered as clear as possible 
through double filter papers (Schleicher and Schull paper No. 595) 
and washed to a volume of 500 cc. Chlorine was determined in 200 
cc. aliquots of the solution, in the manner recommended by Hille- 
brand (30, p. 183). The results appear in Table 8. 



Table 8. — Content of water-soluble chlorine in air-dried Wisconsin soils. 



Type of soil. 


Chlorine, percent 
in air-dry soil. 


Chlorine, pounds 
per acre foot." 




0.005 


150 




0.009 


270 




0.008 


240 


Spooner sand 


0.005 






0.019 


380 



^ The following values were ascribed per acre-foot of air-dry soil : Peat, 
2,000,000 pounds ; loam and clay, 3,000,000 pounds ; and sand, 3,500,000 pounds. 



From the data given by Hopkins (32, Tables 23, 131b) the annual 
removal of chlorine per acre by common crops may be calculated to 
range approximately from 5 pounds in cereal grains (seed only) to 50 
pounds for the sugar beet (root only). Tobacco ranks high as a 
chlorine-absorbing plant, the leaves and stems accumulating 125 
pounds of the element per acre, in some cases. Hays and straws ac- 
count for the annual removal of about 30 pounds of the element per 
acre. These considerations indicate the inadequacy of the soil supply 
of chlorine for maintaining the usual plant content of the element in 
cropping systems. 

Leaching is apparently a more serious factor than cropping in the 
annual depletion of soil chlorides, but both are partly compensated 
by the chlorine compounds washed to the soil in rain. At the Rotham- 
sted Experiment Station, Lawes, Gilbert, and Warington (40, p. 
263-266, 346, 347) found the loss of chlorine in subsurface drainage 
waters to be approximately equal to the supply from rain, fluctuating 
with the latter'. As remarked by these authors, the chlorine content 
of rain usually decreases with the distance from the ocean. The an- 
nual supply per acre at Rothamsted was found to be 13.4 pounds, the 



24 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



content per unit of precipitation being about 2.5 times as great in 
winter as in summer. Vituynii (67) reports average annual precipi- 
tations per acre of from 7.4 to 20.5 pounds of chlorine at eight Russian 
stations; and Knox (38) found a corresponding fall of nearly 37 
pounds at Mt. Vernon, Iowa, during only eight months, from summer 
to spring. The latter unusual observation may be explained by sup- 
posing that chlorides had been transported by wind from the arid 
regions farther west. 

In the present investigation 30 inches of rainfall for the period from 
July to September, inclusive, 191 5, contained 5.9 pounds of chlorine 
per acre, while 43 inches of precipitation for the period from July to 
October, inclusive, 1917, contained 6.3 pounds of chlorine. From No- 
vember to January, inclusive, 1917-18, 36 inches of snowfall (equiv- 
alent to 3.5 inches of rain) contained 1.7 pounds of chlorine. At these 
rates the total annual atmospheric supply- of chlorine per acre at Mad- 
ison is approximately 16 pounds, equivalent tO' 26 pounds of NaCl. 
This value probably exceeds the average, for the partial rainfall ex- 
amined in 191 5 was equal to the normal annual precipitation for this 
region. For the periods here observed the chlorine supply per acre- 
inch of precipitation in equivalents of rain is about 0.2 pound for 
rain and 0.5 pound for snow, which agrees with the findings at Roth- 
amsted. The higher chlorine supply of the winter months may be 
due to an inclusion of wider areas by storms in the drier atmosphere 
of these months, as compared with summer, more distant sources of 
the element thus being brought into play. Increased combustion of 
fuel might also enhance the atmospheric supply of chlorine in winter. 

From the foregoing consideration it appears that the chlorine con- 
tent of soils in humid regions tends toward a minimum, the magni- 
tude of which is largely determined by the chlorine content of the 
rainwater and the nature of the crops removed. If a certain chloride 
content of the soil is essential for the best production of some crops it 
is quite possible, and even probable, that the value of this minimum 
may be too low. Under these conditions the use of common salt in 
conjunction with the usual fertilizers should become a practical con- 
sideration, as indicated by some of the results considered above. 

EFFECTS OF CHLORIDES UPON THE SOIL. 

It has been contended by various authorities that sodium chloride 
may favor plant growth by liberating potassium. The results of 
Schulze (54) seem to indicate quite conclusively, however, that this 
efifect is not universally important. To one portion of a sand-loam 



TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 2$ 

mixture he added a potassium-containing zeolite, to another portion 
the zeoHte was applied with sodium chloride, and a control portion 
was left untreated. Both treated soils gave greater yields of white 
mustard than did the control. The yield where NaCl was applied 
was about twice as great as where the zeolite was used alone, but the 
potassium content of the plants was the same from the two fertilizer 
treatments. From these results Schulze concluded that sodium served 
directly as a plant nutrient. 

Experiments with oats led Soderbaum (60) to believe that NaCl 
acted directly upon the plant by virtue of its chlorine content. He 
employed three portions of a soil deficient in chlorine, to each of 
which was added a complete fertilizer containing one of the following 
salts as a course of nitrogen, namely, NaNO.,, (NH^)oS04, and 
NH4CI. Sodium chloride, equivalent in amount to the NaNO., used, 
was added to similarly fertihzed portions of the soil. The total yield 
was increased by NaCl, when this was added with the first two 
sources of nitrogen, but not when it was added with NH^Cl. Hence 
the benefit derived from NaCl was thought to be specifically due to 
its chlorine content. 

There remains the possibiHty of indirect action of chlorides upon 
plant growth, as by influencing the soil flora in such manner as to 
alter the fertility of the soil. In this connection it may be mentioned 
that C. B. Lipman (41) found NaCl toxic to ammonifying bacteria, 
but stimulating to nitrifying and nitrogen-fixing organisms, at rates 
of application from 0.05 to 0.5 percent, on the basis of dry weight, 
in a sandy soil. Greaves (20) observed stimulation of ammonifica- 
tion in a sandy soil by NaCl at a concentration of about o.oi percent, 
although the salt was toxic at twice that concentration. Greaves' 
smaller appHcation is equivalent to about 350 pounds of salt per acre- 
foot of soil, an amount found favorable in the fertilizing tests already 
described. Other chlorides differed widely from NaCl in their effects 
on ammonification, as noted by Greaves. He states that the same 
concentration of sodium chloride is required to reduce ammonifica- 
tion and the yield of wheat in the field, each to half the normal value. 
It seems, from the preceding citations, that chlorides may affect the 
growth of higher plants by altering the biological production of avail- 
able nitrogen compounds in the soil. Nevertheless, from the known 
limited influence of fertilizers upon the composition of plants and in 
view of the variable response of different plant species to the appli- 
cation of chlorides under similar conditions, this supposition seems 
quite inadequate to explain the changes of plant composition produced 
by these salts. 



26 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

POSSIBLE MECHANISM OF CHLORINE EFFECTS WITHIN THE PLANT. 

Nothing is known as to how NaCl and other chlorides may bring 
about such physiological responses in plants as are here mentioned. 
Many physiological responses to the presence of inorganic salts have 
been regarded by Loeb (44, p. 78-95) and others as due to changes 
in ion-protein compounds within the living protoplasm. In his theory 
of ion-protein compounds Loeb postulates the formation and disrup- 
tion of such compounds by enzyme action. Livingston (42, p. 22, 23) 
has advanced a somewhat similar hypothesis to account for the tox- 
icity and stimulating influence of certain metals to plants. If chlo- 
rine is involved in organic compounds of the plant these must be very 
unstable. Evidence to this end is furnished by the work of Schmidt 
(53), who found the entire chlorine content of sugar beet seed to be 
soluble in water and capable of direct precipitation by AgNOg. This 
may be regarded as strong evidence of the absence of any consid- 
erable amounts of organic chlorine compounds in this seed. It there- 
fore appears probable that the chlorine of the sugar beet, and perhaps 
of other plants, exists in the cells largely as inorganic chlorides, com- 
parable to those absorbed from the soil. 

The apparent relation of chlorine content to accumulation of starch 
in the potato tuber (Pfeifl^er et aL, 49) suggests enzyme activity as a 
main controlling condition for this effect. That chlorides which may 
readily exist in plant cells greatly accelerate the action of ptyalin of 
the human saliva is clear from the work of Wohlgemuth (77). Cole 
(14) obtained similar results with ptyalin, but found that the action 
of invertin was considerably retarded by NaCl. Stimulation of 
diastatic enzymes from plant sources by the action of chlorides has 
been observed by Kellerman (36) and by Hawkins (28). 

If, supported by the foregoing evidence, we suppose that the con- 
centration of chlorides in the cell may exert marked controlling influ- 
ence upon the activities of intracellular enzymes, especially the dia- 
static ones, and if we suppose that many vital activities of the plant 
are controlled in their turn by enzyme action, we arrive at a general 
suggestion of a possible way by which variations in the concentration 
of these salts may bring about such physiological responses as have 
been observed.' This hypothesis is, of course, very general in its 
nature and only tentative, but it may serve to connect the various facts 
as we know them at present. As more information accumulates this 
suggestion may be elaborated, modified, or discarded, as may be 
determined. 



TOTTINGHAM : IXFLUEXCE OF CHLORIDES ON PLANT GROWTH. 2/ 

Summary. 

A survey of previous field and greenhouse investigations of the 
effects of chlorides upon the growth and composition of plants dis- 
closes extremely variable results. It is apparent that the species of 
plant, the type of soil, and especially the complex of factors consid- 
ered as climate, greatly influence these effects. 

In the present investigation the introduction of potassium and 
sodium chlorides into water cultures but slightly affected wheat plants 
during the first five weeks after germination. Buckwheat grown to 
apparent maturity in similar cultures was decidedly affected by the 
application of these chlorides. Although seed production remained 
apparently undisturbed, the length of roots and the yield of dry 
matter was depressed. The least production of dry matter in leaf 
blades and the greatest depression. of water absorption per unit of dry 
matter of the foliar tissue occurred in the presence of sodium chloride. 

The radish responded only sHghtly, in yield and composition, to the 
application of potassium and sodium chlorides along with complete 
fertilizer in soil cultures in the greenhouse. Under similar condi- 
tions, increased production of dry matter and of the percentages of 
sugars therein resulted with the carrot, while the reverse was true of 
the parsnip. In the latter case sodium chloride was particularly 
injurious. 

The sugar beet gave the same general responses to chlorides as 
did the carrot, when grown in the greenhouse. While the roots were 
more watery where chlorides were applied, the yield of dry matter 
was greatly increased. The dry matter of such roots contained more 
glucose, but less sucrose, than that obtained from cultures in soil not 
receiving chlorides. Similar responses followed the application of 
common salt alone to beets grown in the field. 

The potato produced increased yields of dry matter in the tuber 
when potassium chloride was supplied in place of potassium sulfate, 
in a complete fertilizer ration, to soil cultures in the greenhouse. 
Relative to the percentage of starch, the Rural New Yorker and 
Triumph varieties of potato responded dift'erently, the former being 
depressed while the latter was unaffected. The results indicated that 
the variety of plant was more important than the type of soil in 
determining this effect of chlorides. In field cultures in a dry season 
the application of potassium chloride in a complete fertiHzer de- 
creased the yield of dry matter in the tubers, but not the percentage 
of marketable tubers, of the Triumph variety. In a season which was 
very humid toward its close, no significant differences in composition 



28 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



or cooking quality were found between tubers of the Rural New 
Yorker variety produced where potassium sulfate and potassium 
chloride were employed separately in a complete fertilizer ration. 
Sodium chloride applied alone altered the composition of the tubers 
only slightly in this test, but affected their quality seriously. 

Determinations of the water-soluble chlorides in several types of 
Wisconsin soils have shown them to be equivalent to about 150 to 
380 pounds of chlorine per acre- foot. It is shown that this supply is 
inadequate for long maintaining the usual plant content of the ele- 
ment in crop rotations. The annual supply of chlorine in rain and 
snow at Madison is about 16 pounds per acre, but, judging from condi- 
tions at the Rothamsted Experiment Station, this acquisition is prob- 
ably counterbalanced by losses in drainage waters. 

Evidence is cited which indicates that sodium chloride serves directly 
as a fertilizer, and that chlorine is the active element therein. Further 
evidence indicates a possible role of chlorides in stimulating the 
biological production of available nitrogen compounds in the soil, but 
this eft'ect seems inadequate for explaining all of the, varied responses 
of higher plants to the application of chlorides. 

Proceeding from the observed effects of chlorides upon diastase and 
other enzymes which act upon carbohydrates, a tentative hypothesis 
is advanced to explain the varied physiological responses of plants to 
chlorides through regulation of enzyme activity by these salts. 

On the whole, it appears quite possible that further investigation 
may lead to the development of practical rules for the use of chlorides 
in agriculture in such ways as to increase and improve certain crops, 
due account being taken of those crops injured by these salts, as well 
as of climatic and soil conditions. 

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TOTTINGHAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 29 

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I. Ammonification. /w Centbl. Bakt., Abt. 2, 32 : 58-64. 1911. H. Nitri- 
fication, ibid., 32: 305-313. 1912. HI. Nitrogen fixation. Idem, and L. 
T. Sharp. Ibid., 35 : 647-655. 1912. 

42. Livingston, B. E. Chemical stimulation of a green alga. In Bui. Torrey 

Bot. Club, 32: 1-34. 1904. 

43. . Atmometry and the porous cup atmometer. In The Plant World, 

18: 21-30, 51-74, 95-III, 143-149- 1915- 

44. Loeb, Jacques. Concerning a theory of irritability and the role of Na, K 

and Ca for animal life. The Dynamics of Living Matter, xi -|- 233 p. 
New York, 1906. 

45. LoEW, Oscar. The physiological role of mineral nutrients in plants. U. S. 

Dept. Agr., Bud. Plant Indus. Bui. 45, p. 25, 26. 1903. 



TOTTINGIIAM : INFLUENCE OF CHLORIDES ON PLANT GROWTH. 3 1 

46. Lyon, T. L., and Wiaxcko. A. T. Experiments in the culture of the sugar 

beet in Nebraska. Nebr. Agr. Expt. Sta. Bui. 81. 1903. 

47. Nernst, Walter. Theoretical Chemistry (translation by Tizard), xix-|-8io 

p. London, 1911. 

48. NoBBE, Friedrich. and Siegert, Theodor. Uber das Chlor als Specifische 

Nahrstoff der Buchweizenpflanze. In Landw. Vers. Stat., 4: 318-340, 
1862; 5: 1 16-136, 1863; 6: 108-120, 1864; 7: 371-386, 1865; 8: 187, 188, 
1866. 

49. Pfeiffer, Th., Franke, E., Lemmermann, O., and Schillbach, H. tiber 

die Wirkung verschiedener Kalisalze auf zusammenset'zung und den 
Ertrag des Kartoffeln. /;/ Landw. Vers. Stat., 49: 349-385. 1898. 

50. PiRSsoN, Louis V. Rocks and Rock Minerals, iv + 414 p. New York, 

1913- 

51. Plate, F. The action of isolated chlorides on the germination period of 

Avena sativa. In Chem. Abs., 9: 1070. 1915. 

52. Prianishnikov, D. Results of vegetation experiments in the years 1901- 

1903. Abs. in Expt. Sta. Rec, 18: 320, 321. 1906. 

53. Schmidt, E. W. The effects of chlorides on plant growth. Unpublished 

thesis submitted for the degree of B.Sc, Univ. of Wis., Madison, 1915. 

54. ScHULZE, B. Die Dungewirkung des Chlornatriums. I)i Landw. Vers. Stat., 

86: 323-330. 1915- 

55. Shelton, E. M. Experiments with wheat. Kans. Agr. Expt. Sta. Bui. 4, 

p. 45-48. 1888. Salt as a fertilizer. Kans. Agr. Expt. Sta. Bui. 7, p. 
83-86. 1889. Salt as a fertilizer for oats. Kans. Agr. Expt. Sta. Bui. 
29, p. 176, 177. 1891. 

56. Sherman, H. C. Methods of Organic Analysis, 407 p. New York, 1912. 

57. Shive, J. W. A three-salt nutrient solution for plants. In Amer. Jour. 

Bot, 4: 157-160. 191 5. 

58. . A study of physiological balance in nutrient media. In Physiol. Re- 
searches, 1 : 327-397. 191 6. 

59. Shulov, I. S. Various smaller experiments with fertilizers and soils. Abs. 

in Expt. Sta. Rec, 22: 223, 224. 1910. 

60. Soderbaum, H. G. The fertilizing action of common salt. Abs. in Expt. 

Sta. Rec, 26: 623. 1912. 

61. Stone, W. E. The carbohydrates of wheat, maize, flour, and bread. U. S. 

Dept. Agr., Off. Expt. Sta. Bui. 34, 44 p. 1896. 

62. SucHTiNG, H. tiber die schadigende Wirkung der Kalirohsalze auf die 

Kartoffel. In Landw. Vers. Stat., 61 : 397-449. 1905. 

63. Taft, L. R. Fertilizers upon potatoes. Mich. Agr. Expt. Sta. Bui. 131, 

p. 10, II. 1896. 

64. Takeuchi, T., and Ito, S. Note on the injurious effect of chloride. In 

Bot. Mag., 25: 132, 133. 1911. 

65. ToTTiNGHAM, W. E. A quantitative chemical and physiological study of 

nutrient solutions for plant cultures. In Physiol. Researches, i : 133-245. 
1914. 

66. Trelease, S. F. A study of salt proportions in a nutrient solution contain- 

ing chloride, as related to the growth of young wheat plants. Johns 
Hopkins Univ. Circ, p. 222-225. March, 1917. 

67. ViTUYNii, S. Amounts of chlorine and sulphuric acid in rain water. In 

Chem. Abs., 6: 908. 1912. 



32 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

68. VoELCKER, Augustus. Experiments with salt upon mangolds. In Jour. 

Roy. Agr. Soc. England, 25 : 385-390. 1864. 

69. . Field experiments on root crops. In Jour. Roy. Agr. Soc. England, 

2d ser., 3 : 500-530. 1867. 

70. . Field experiments on clover seeds and permanent pasture. In Jour. 

Roy. Agr. Soc. England, 2d ser., 5 : 73-97. 1869. 

71. . Field experiments on potatoes. In Jour. Roy. Agr. Soc. England, 

2d ser., 6: 392-415. 1870. 

72. VoELCKER, J. Augustus. Salt experiments upon barley. In Jour. Roy. Agr. 

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ments, p. 21, 22. 1908. 

74. Wagner, P. Wassercultur Versuche mit Mais. In Landw. Vers. Stat., 13 : 

218-222. 1871. 

75. Wheeler, Homer J. Manures and Fertilizers, xxi -j- 389 p. New York, 

1913. 

76. , and Hartwell, B. L. Conditions determining the poisonous action 

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Also the following, authorship not stated : 

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Ann. Rpt, p. 139-141. 1891. 



ARNY AND GARBER : DETERMINING PLOT YIELDS. 



33 



FIELD TECHNIC IN DETERMINING YIELDS OF PLOTS OF 
GRAIN BY THE ROD-ROW METHOD. 

A. C. Arny AND R. J. Garber. 
Introduction. 

Determining the yields of grain on varietal, rotation or soil fertility 
plots or on large fields by harvesting portions of the areas is fre- 
quently desirable or necessary. Th^ necessity may arise at outlying 
fields where tests are made in cooperation with farmers or at substa- 
tions where facilities are lacking for harvesting or thrashing accurately 
the product of the entire areas. Also, it is frequently desirable to 
harvest portions of plots as a check on the yields obtained from 
harvesting the entire areas. 

The value of any method used for this purpose depends upon 

(a) the degree of precision which may be obtained from its use, 

(b) the labor required, and (c) ease'of manipulation. In the present 
paper, data are given (a) on the precision obtained by determining 
yields by the removal of rod rows from tenth-acre plots as compared 
with harvesting and thrashing the entire plots, and (b) the compara- 
tive labor requirements of determining yields by the two methods. 

Review of Literature. 

McCall (3)- gives directions for making an apparatus to be used 
in measuring ofif areas of 1/5,000 acre in grain or grass plots. An 
outline of a plot is given showing the location of five areas, making 
a total of 1/1,000 of an acre, which were removed from each plot 
of wheat and timothy in a preliminary trial. The statement is made 
that the results secured by this method checked quite satisfactorily 
with the yields ascertained by harvesting and thrashing the product of 
the entire plots. The inclusion of border rows in each area harvested 
is a serious objection to the use of the method as outlined, especially 
in varietal test plots. Removal of at least two border rows from 
either side of each plot before taking the samples would tend to 
remove this objectionable feature. 

Arny and Hayes ( i ) show that increase in yield due to the utiliza- 
tion of alley space by the two border rows on the sides only of plots 

1 Published with the approval of the Director as Paper No. 132 of the Journal 
Series of the Minnesota Agricultural Experiment Station, University Farm, 
St. Paul, Minn. Received for publication August 20, 1918. 

2 Reference is to " Literature cited," p. 47. 



34 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

8.25 feet wide and 132 feet long varied from 748 to 15.78 percent, 
with an average of 12.78 percent, for 11 varieties of oats. For 5 
varieties of wheat, the increase in yield from this cause varied from 
14.07 to 23.51 percent, with an average of 18.41 percent. For 4 
varieties of harley the increase in yield ranged from 14.28 percent to 
24.13 percent, with an average of 20.64 percent. The grain was 
drilled in 6-inch rows. The results indicate that alley effect extends 
over an area at least i foot in width within the margins of plots and 
that some varieties utilize alley space more efficiently than others. 
Therefore, the inclusion of border rows, particularly in varietal plots 
surrounded by alleys, may introduce a source of error sufficiently 
great to offset any superiority in ability to yield which one variety 
may have over another. 

Hayes and Arny (2) present data which indicate that three or four 
systematically replicated rod rows spaced i foot apart, sown at the 
regular field rate, when the possible effect of competition between 
varieties is overcome by border rows, are about as accurate as any 
number below nine. 

Material and Methods. 

The Soils Division has in progress at University Farm and at the 
several substations fertilizer experiments conducted on a uniform 
plan. The treatments in addition to the check are designated as 
treatments A, B, C, D, and E. Each treatment is repeated three 
times. The plots are 2 rods wide by 8 rods long, or approximately 
one-tenth acre in size. The drill rows are 6 inches apart. On 
each series devoted to this work, lime is applied crosswise to half of 
each plot. On account of the difficulty of dividing accurately the 
grain on the limed and unlimed halves, these yields in 1917 were 
determined by removing and thrashing separately four definitely 
spaced rod rows of the grain from each half plot. The yields of the 
limed and unlimed portions, as determined by this method, will be 
published by the Soils Division. The results from the eight rod rows 
used in determining the yields of the limed and unlimed portions, 
together with the results from a ninth row removed at the same time 
from approximately the center of each plot, have been combined in 
various ways and compared with the yields ascertained by harvesting 
the entire plots. 

The location of each rod row within a plot is shown in figure i. 
At the Morris substation, the drill rows ran crosswise of the plots 
and the plan was modified to meet the conditions. 



ARNY AND GARBER I DETERMINING PLOT YIELDS. 



35 



A piece of straight-grained oak i rod in length and three-quarters 
by a half inch in thickness was used in measuring off the rod rows. 
A measure of this kind was found very convenient, but any other 
sort of a rod stick would have served the purpose. In the removal 
of the rod rows of grain in any one experiment the worker always 
started in the same corner of the plot. Assuming that he started at 
the northeast corner, he first counted south to the fifth drill row and 
stepped into the plot 5 feet or two short paces. Rod row No. i was 
then laid oft* and the grain was pulled or cut, bound, and tagged. The 
worker then walked south to the twenty-fifth drill row and west 
10 feet or three paces, removed rod row No. 2, and continued the 
round, harvesting the rod rows in numerical order. The nine small 




Fig. I. Outline of plot showing the location of the rod rows. Row i is the 
5th row, 2 feet from the end; Row 2, 15th row, 24.5 feet from end; Row 3, 
34th or 35th row midway from ends; Row 4, i6th row, 24.5 feet from end; 
Row 5, 6th row, 2 feet from end; Row 6, 6th row, 2 feet from end; Row 7, 
i6th row, 24.5 feet from end; Row 8, 15th row, 24.5 feet from end; Row 9, 5th 
row, 2 feet from end. 



bundles were then carried out and the heads or panicles removed 
by laying the bundles over the edge of a box and using a hookshaped 
cornknife with serrated blade to cut the straw. The heads or panicles 
of each rod were then placed in a flour bag and hung up under the 
eaves of a building to dry. At the substations, the flour bags contain- 
ing the unthrashed grain were placed in large jute bags and shipped 
to University Farm. After being thoroly dried, the grain in each 
bag was beaten out by hand and separated from the straw and chaff 
by running thru a fanning mill. In this trial, in order that the 
different combinations could be made for comparison with the yield 
secured from harvesting the entire tenth-acre plot, the yield of grain 
from each rod row was necessarily determined separately. In the 
actual use of this method in ascertaining yields, the rod rows harvested 
from each plot need not be kept separate. 



36 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The combinations of the yields of rod rows for comparison with 
the yields ascertained by harvesting the entire tenth-acre plots includ- 
ing what was removed in the rod rows, were made as follows. For 
the determination by 4 rows, the yields of row numbers 2, 4, 7, and 8 
were averaged ; for the determination by 5 rows, the yields of row 
numbers i, 3, 5, 6, and 9 were averaged; and for the determination by 
9 rows, the yields of all the rows removed from each plot were aver- 
aged. The yields from the three plots as determined by harvesting 
the entire tenth acre, 9, 5, and 4 rod rows are averaged to obtain the 
yield for the check and for each treatment. 

In making direct comparisons of the value of the several treatments 
indicated by the yields as determined from harvesting- the entire plots 
and from the rod rows removed from the plots, the least percentage 
difference which is taken as significant was derived by the pairing 
method employed by Wood and Stratton (4). 

In deriving the probable errors used in discussing the results from 
the tenth-acre plots and from the rod rows, the yields of each con- 
secutive pair of plots receiving the same treatment were averaged and 
the deviation from the mean of each pair ascertained. Each devia- 
tion was then calculated to a percentage of the mean yield of the 
pair. The different steps in deriving the deviation in percentage of 
the mean of each pair are made clear by using the yields per acre 
of the three check plots of oats numbered i, 7, and 13 in the test at 
University Farm, which are 77.8, 73.3, and 80.7 bushels respectively, 
as shown in Table i. 



Table i. — Yields of plots of oats similarly treated, with percentage deviations 

of mean of each pair. 



Plot numbers. 


Average yield in 
bushels per acre of 
pairs of similarly 
treated plots. 


Deviations in bush- 
els per acre from 
the mean yields of 
the pairs. 


Deviation in per- 
centage of mean of 
each pair. 


Deviation in per- 
centage of each 
pair squared. 


I and 7 

7 and 13 


75-6 

77.0 


2.3 
3-7 


3-04 
4.81 


9.24 
23-14 



After the deviation in percentage of the mean of each pair had 
been ascertained, the arithmetical mean of the total number of per- 
centage deviations was calculated. This gave the probable error for 
a single determination in percentage of the mean. The results for 
the 168 pairs of tenth-acre plots and the 432 pairs of rod rows were 
plotted in frequency curves, which are shown in figure 2. 



ARNY AND GARBER : DETERMINING PLOT YIELDS. 



37 



The probable errors in percentage of the mean yields from the 
tenth-acre plots vary from 3.56 percent for the oats at Morris to 
10.10 percent for the oats at Duluth. Where the results from all the 
plots are considered, the probable error in percentage of the mean 

5-35- The mean probable errors for the tenth-acre plots and rod 
rows of oats and wheat at the various stations are shown in Table 2. 



Table 2, — Mean probable errors for yields of the tenth-acre plots and the rod 
rows in percent of mean yield of each pair and in percent of mean 
yield of each pair squared. 



Crop and location. 



No. of pairs. 



Probable errors 
in percent of 
mean. 



Probable errors 
in percent of 
mean squared. 



Tenth-acre plots: 

Oats at Duluth 

Oats at Morris 

Oats at University Farm . . 

All oats 

Wheat at Morris 

Wheat at University Farm 

All wheat 

All oats and wheat 

Rod rows: 

Oats at Duluth 

Oats at University Farm . . 
Wheat at University Farm 

Wheat at Morris 

All oats and wheat 



12 
36 
48 
96 
36 
36 
72 
168 



108 
108 
108 
108 
432 



10.10 
3.56 
4.87 
5.03 
5.06 
6.50 
5.78 
5-35 



13.69 
9.12 
9.69 
7-75 
9.98 



14-74 

4- 79 

5- 47 
7.22 
9.36 
9-52 
7.00 
7.12 



16.83 
11.59 
12.29 

9-95 
12.93 



For the rod rows the mean probable errors vary from 7.75 percent 
for the wheat at Morris to 13.39 percent for the oats at Duluth. 
When the total number of rows is included, the mean probable error 
is 9.98 percent. The probable error for the tenth-acre plots, 5.35 
percent, is practically identical with that given by Wood and Stratton 
(4) for plots above _3^-acre in size. For the rod rows, which are 
g-.y-g-^ -acre in size, the probable error is somewhat lower than that 
given by Wood and Stratton. 

Work with a large number of similarly treated plots in other experi- 
ments indicates that squaring the deviation in percent of the mean 
for each pair before calculating the arithmetical mean and afterwards 
extracting the square root gives a probable error more nearly ap- 
proaching that ascertained by expressing in percentage of the mean 
the probable error for a single determination derived in the ordinary 
way. Inspection of the probable errors ascertained by the squaring 
method as compared with those not squared, as given in Table 2, 
shows the former to be higher in each instance. 



38 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



For the reason that the probable errors derived by the squaring- 
method more nearly approach those derived by the ordinary method 
and that they are higher and hence more conservative, they are used 
in the following discussion. 



ISM 


















































-V 


























res 










L 


4 


































j 
















- 






























— 
























j 














































\ — ' 


















































j 










feo 
*5 












































/ 
















1 














30 
>9 






7 





















rf 





r- 














































iec:.E.i 








o 2 


3 

1 r>-iE 


o ^ 




b -3 
• F-EI 


o - ao - 1 

i 


PI 






O 3 
>n mi: 


f\n. 



Fig, 2. At left, normal probability curve for 432 pairs of similarly treated 
rows; at right, normal probability curve for 168 pairs of similarly treated tenth- 
acre plots. 



Taking 7.12 percent as the probable error for a yield determined 
on any single tenth-acre plot, then for yields from plots repeated three 

7 12 

times the error would be or 4.12 percent. For the rod rows 

V3 

the probable error of a single determination was found to be 12.93 
percent and hence, for the mean of one rod row in each of three 



repeated plots the error is 



1^-93 
V3 



or 7.47 percent. For rod rows re- 



peated nine, five, and four times in each of three similarly treated 

7-47 7-47 
tenth-acre plots, the probable errors are or 2.49 percent, — 

V9 V5 

7 47 

or 3.34 percent, and or 3.79 percent, respectively. 
V4 

The odds are 30:1 against a deviation of 3.81 times its probable 
error in one direction only being due to normal variation (4). 



ARNY AND GARBER : DETERMINING PLOT YIELDS. 



39 



Multiplying the errors in percent, 4.12, 2.49, 3.34, and 3.79, by 3.81, 
the least significant difference between any two treatments is found 
to be 15.70 for three similarly treated tenth-acre plots, and 9.49, 12.73, 
and 14.44 respectively for 9, 5, and 4 rod rows removed from triplicate 
tenth-acre plots. 

As the probable errors in percentage of the means squared, for both 
the tenth-acre plots and for the rod rows, are radically greater at 
Duluth than at the other locations, it seems necessary to use these in 
the interpretation of the results at this location instead of the prob- 
able errors derived from considering the yields of all the plots or 
rows. The probable errors for the yields for a single determination 
of the oats at Duluth derived by the squaring method are 14.74 per- 
cent for the tenth-acre plots and 16.83 percent for the rod rows re- 
spectively. For three tenth-acre plots of the same treatment, the 

error is i^^^^ or 8.51 percent, and for a rod row removed from each 
V3 

of three similarlv treated tenth-acre plots, the error is ^^'^-^ or 9.72 

V3 

percent. For rod rows repeated 9, 5, and 4 times in each of three 

Q 72 

similarly treated tenth-acre plots, the errors are or 3.24 percent, 

V9 

9.72 , Q.72 . , 

— ^ or 4.35 percent, and — — or 4.86 percent, respectively. 

V5 V4 

Multiplying the errors in percentage for the work at Duluth, 8.51, 
3.24, 4.35, and 4.86, by 3.81, the least significant difference in percent 
between any two treatments is 32.4 for three similarly treated tenth- 
acre plots; and 12.34, 16.56, and 18.51 respectively for 9, 5, and 4 
rod rows removed from triplicated plots similarly treated. 

The probable error of the difference between two statistical con- 
stants was determined by taking the square root of the sums of the 
squares of the probable errors of the two constants. 

Relative Precision of Yields from Tenth-Acre Plots and from Rod Rows 

Removed from Them. 

For each location, the yields ascertained by the four methods for 
the three plots of each treatment, together with the mean yield, the 
standard deviation, and coefficient of variability are tabulated. The 
percentage increases for each treatment are also given. 



40 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

RESULTS WITH WHEAT AT THE MORRIS SUBSTATION. 

Examination of the mean yields in Table 3 for the check and the 
various fertilizer treatments show a close agreement for the deter- 
minations by the different methods. 

Table 3. — Comparison of yields and variability of Marquis wheat grown at the 
Morris substation under six different treatments as determined from 
triplicate tenth-acre plots and from g, 5, and 4 rod rows removed 
from tenth-acre plots. 



Fertil- 
izer 
treat- 
ment. 


Source. 


Yields in bushels per 
acie for each of the 
triplicate plots. 


Means. 


Standard 
deviations. 


Coefficients of 
variability. 


Check 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


28.10 
25-97 
24.42 
27.96 


29.50 
29.96 
32.50 
26.86 


26.62 
26.86 
25.10 
29.13 


28.07 ±0.46 
27.60 ±0.67 
27.34dbl.43 
27.98 ±0.36 


1. 17 ±0.32 
1. 71 ±0.47 
3.66±I.0I 
0.93 ±0.26 


4.i7±i.i5 
6.20±i.7i 
13-44 ±3-76 
3.32 ±0.91 


A 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


29.16 
29.29 

28.74 
30.05 


32.53 
31.67 
30.61 
33-07 


30.63 
27.85 
28.98 
26.50 


30.77 ±0.54 
29.60 ±0.62 
29.48 ±0.32 
29.87 ±1.05 


1.38 ±0.38 
1.58 ±0.44 
0.63 ±0.23 
2.69 ±0.74 


4.48 ±1.23 
5.34±i-46 
2.82 ±0.78 
9.01 ±2.48 


B 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


34-04 
32.42 
32.22 
32.74 


33-49 
29.30 
28.56 
30.30 


32.70 
32.09 
34-59 
29.05 


33-41 ±0.21 

3i.27±o.55 
3i.79±o.97 
30.70 ±0.60 


o.55±o.i5 
i.40±o.29 
2.48 ±0.68 
1.53 ±0.42 


1.65 ±0.45 
4.48 ±1.23 
7.80 ±2.15 
4-98 ±1.37 


C 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


29-32 
31.16 
30.71 
30.52 


33.87 
31.76 
30.14 
33-85 


32.53 
31.66 
33-36 
29.61 


31.91 ±0-74 
31.53 ±0.10 

3i.74±0-5i 
31-33 ±0.71 


i.9i±o.53 
0.26 ±0.07 
i.3i±o.36 
1.82 ±0.50 


S.99±i.65 
0.82 ±0.23 

4.i3±i.i4 
5.81 ±1.60 


D 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


36.46 
37-68 
35.78 
40.11 


37-56 
33-36 
33.12 
32.74 


35-20 
31.76 
31-52 
32.14 


36.41 ±0.37 

34- 27 ±0-97 
33-47 ±0.69 

35- 33 ±1-34 


0.96 ±0.26 
2.50 ±0.69 
1.76 ±0.48 
3.44 ±0.95 


2.64±o.73 
7.30±2.io 

5.26±i.45 
9.74 ±2.68 


E 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


34- 76 

35- 20 
36.26 
33-96 


33- 59 
35-27 
35-90 

34- 57 


35-75 
34-55 
37-55 
30.81 


34-70 ±0.34 
35.01 ±0.12 
36.57 ±0.28 
33-11 ±0.64 


0.88 ±0.24 
0.32 ±0.09 
0.71 ±0.20 
1.65 ±0.45 


2.54 ±0.70 
0.91 ±0.25 

1.94 ±0.53 
4.98 ±1.37 



In Table 4 the percentage increases in yield are given for the dif- 
ferent treatments, based on the yield of the check as determined by 
harvesting the entire tenth-acre plots. Using 15.70 percent as the 
least increase that is probably significant for the tenth-acre plots and 
9.49 percent, 12.73 percent, and 14.44 percent, respectively, for the 
9, 5, and 4 rod rows removed from the tenth-acre plots, it is evident 
that treatment A is not significantly better than the check as in- 
dicated by the yields ascertained by each of the four methods. With 
the exception of treatment C, which shows only 13.68 percent increase 



ARNY AND GARBER I DETERMINING PLOT YIELDS. 



41 



over the check as determined by harvesting the entire tenth-acre, and 
treatments B and C where 4 rod rows were removed from each plot, 
treatments B, C, D, and E show significant increases by each method. 



Table 4. — Comparison of the percentage increase in the yields of wheat for 
each fertiliser treatment based on the mean yield of the check at 
the Morris substation. 



Treatment. 


Tenth-acre plots. 


Increase in yield over the check as determined by harvesting 
the stated number of rod rows from each tenth acre. 


Nine rod rows. 


Five rod rows. 


Four rod rows. 




Percent. 


Percent. 


Percent. 


Percent. 


A 


9.62 


7-25 


7.72 




B 


19.02 


13-30 


16.28 


9.72 


C 


13.68 


14.24 


16.09 


11.97 


D 


29.71 


24.17 


22.42 


26.27 


E 


23.62 


26.85 


33.76 


18.33 



■ Table 5, — Comparison of yields and variability of Haynes Bluestem {Minne- 
sota No. 169) wheat grown at University Farm, St. Paul, Minn., under 
six different treatments as determined from triplicate tenth-acre 
plots and from g, 5, and 4 rod rows removed from tenth- 
acre plots. 



Fertil- 
izer 
treat- 
ment. 


Source. 


Yield in bushels per 
acre for each of the 
triplicate plots. 


Means. 


Standard 
deviation 


Coefficients of 
variability. 


Check 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


29.78 
40.97 
38.38 

35-06 


36.24 
40.58 
41-37 
39-41 


27.28 
33.21 
37.30 
27.92 


3i.30il.39 
38.25il.39 
39.02 io.67 
34-13 ±1-85 


3.58i0.99 
3.57io.98 
1.72 io.47 
4.74±i-3i 


ii.44i3-i9 
9.33 i2. 57 

4.41 il.2I 

13.89 i3-90 


A 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


35.05 
37-53 
38.11 
36.16 


31-33 
36.97 
35-37 
38.81 


35.79 
41.91 
42.88 
40.50 


34.06 io. 76 
38.80 io.86 
38.79i1.21 
38.49 io. 70 


1.96 io. 54 
2.21 io.6i 
3.ioio.85 
i.79±o.49 


5-75ii-58 
5.70ii.57 

7.99i2.20 

4.65 ii. 28 


B 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


33-59 

36.34, 

38.20 

35.04 


32.77 
35.66 
35.13 
36.16 


35-53 
36.54 
35-67 
37.46 


33-96 io.45 
36.25 io. 16 
36.23 io.52 
36.22 io.39 


i.i6io.32 
0.41 io.ii 
i.34io.32 
0.99 io.27 


3.42io.94 
i.i3io.3i 
3.69 ii. 02 
2.73 io. 75 


C 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


33.54 
33.48 
33-02 
33-91 


32.59 
35.12 
37.00 
32.61 


34-78 
39.70 
40.85 
37-90 


33-64io.35 
36.10 ii. 02 
36.96i1.25 
34.81 io.88 


0.90 io. 25 
2.63 io.72 
3.20io.88 
2.25 io.62 


2.68 io.74 

7.29i2.0I 

8.66i2.38 
6.46ii.78 


D 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


34.92 
38.69 
40.07 
36.80 


31.57 
31.67 
30.82 
32.37 


36.55 
39.69 
43.61 
34-61 


34-35 io. 81 
36.68 ii.39 
38.17 i2. 10 
34-59 io.70 


2.07 io. 57 
3.57io.98 
5.39ii-48 
1. 81 io.50 


6.03 ii.66 
9.73 i2. 68 
14.12 i3.96 
5.23 ii. 44 


E 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


33- 73 

34- 85 
33-05 
36.96 


30.78 
32.89 
31-43 
34.57 


36.51 
37-23 
38.02 
36.08 


33- 67 io.91 

34- 99 io.69 
34.16i1.09 

35- 87 io.39 


2.34 io. 64 
i.77io.49 
3.81 io.77 
0.99 io.27 


6.95ii.9i 
5.o6ii.39 
8.23 i2.27 
2.76 io. 76 



42 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

RESULTS WITH WHEAT AT UNIVERSITY FARM, 

The yields for the individual plots for each treatment of wheat at 
University Farm, with the mean, standard deviation, and coefficient 
of variability, are given in Table 5. 

Due to the higher yield of the border rows in plots separated by 
alleys as compared with the rows farther within the plots, the expec- 
tation is that the yields from harvesting the entire plots will be higher 
than from harvesting all or portions of the interior of the same plots. 
Here the yields from harvesting the entire plots are lower than those 
secured by harvesting portions of the interior of the same plots (i). 
In this instance, the diflference may be due in part to the loss of grain 
in harvesting with the binder, as the wheat was of the easily shattering 
Bluestem variety and was badly lodged. In Table 6 are given the 
percentage increases in yield for each treatment based on the mean 
yield of the check plots. 



Table 6. — Comparison of the percentage increases in the yields of wheat for 
each fertiliser treatment based on the mean yields of checks at 
University Farm. 



Treatment. 


Tenth-acre plots. 


Increase in yield over the check as determined by harvesting 
the stated number of rod rows from each tenth acre. 


Nine rod rows. 


Five rod rows. 


Four rod rows. 




Percent. 


Percent. 


Percent. 


Percent. 


A 


8.82 


1.44 




10.83 


B 


8.50 






4.29 


C 


7.48 






0.23 


D 


9-74 








E 


7.57 






3.28 



The yields from harvesting the entire plots show some increase in 
yield for each treatment as compared with the yield of the check, but 
the increase is not a significant one in any instance. For the 9-row 
method except for treatment A, the yield of the check is greater than 
the yield from the treated plots. For the 5-row method the yield of 
the check is higher than for any of the treated plots. No significant 
increases in yields due to treatment are indicated by the 4-row method. 

RESULTS WITH OATS AT UNIVERSITY FARM. 

Inspection of the mean yields for the three similarly treated plots 
as determined by the four methods shows the yields ascertained by 
the 5-row method to be as high or higher than those from the tenth- 
acre plots, while the yields from the four and nine rod rows are 
lower. This suggests a possible border effect in oats on the fifth row 
from the sides of the plots. The data on yields are given in Table 7. 



ARNY AND GARBER : DETERMINING PLOT YIELDS. 



43 



Table 7. — Comparison of yields and variability of Ligowa (Minnesota No. 281) 
oats grown at University Farm, St. Paul, Minn., under six different 
fertilicer treatments as determined from triplicate tenth-acre 
plots and from g, 5, and 4 rod rows removed from 
tenth-acre plots. 



Fertil- 
izer 
treat- 
ment. 


Source. 


Yield in bushels per 
acre for each of the 
triplicate plots. 


Means. 


Standard 
deviations. 


Coefficients of 
variability. 


Check 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


77.83 

04.01 
83.68 
79.63 


73-31 

07.00 

73-34 
61.09 


80.72 
75-87 
83.32 
63.38 


77.29 ±1.19 
76.11 ±2.66 
81.78 ±2.48 
68.03 ±3.21 


3.05 ±0.84 
6.84±1.88 

6.36±1.75 
8.25 ±2.27 


3-95 ±1.09 
8.99 ±2.48 
7.78 ±2.14 
i2.i3±3-39 


A 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


82.67 
83.23 
92.14 
72.20 


80.64 
70.38 
75-50 
64.07 


81.48 
85-13 
85.12 
85-25 


81.60 ±1.02 
79-58 ±2.55 

84.25 ±2.66 
73-84±3-40 


2.63 ±0.72 
6.55±i.8o 
6.82±i.88 
8.72 ±2.40 


3.22 ±0.89 

8.23 ±2.27 
8.09 ±2.23 

II. 81 ±3.30 


B 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


85.76 
86.97 
88.29 

85-44 


77-98 
74.70 
77.07 
71.82 


79-90 
81.21 
84-87 
76-73 


81.21 ±1.29 
80.96 ±1.95 
83.41 ±1.83 
78.00 ±2.19 


3.31 ±0.91 
5.01 ±1.38 
4.70±i.29 
5.63±i.55 


4.08 ±1.12 
6.19 ±1.70 
5.63 ±1.55 
7.22 ±1.99 


C 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


86.02 
84.36 
83.31 
85-79 


79-25 
78.46 
82.85 
73.06 


80.79 
80.22 
83.27 
76-52 


82.02 ±1.13 
81.01 ±0.96 
83.i4±o.o8 
78.46 ±2.09 


2.90 ±0.80 
2.47 ±0.68 
0.21 ±0.06 
5.37 ±1.48 


3.54 ±0.97 
3.05 ±0.84 
0.25 ±0,07 
6.84±i.88 


D 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


85-64 
79-87 
83.08 

75-95 


76.73 
72.78 
75-34 
69.68 


87.88 
86.93 
91.40 
81.45 


83.41 ±1.88 
79.86 ±2.25 
83.27 ±2.55 
75-69±i.87 


4.82 ±1.33 

5.78±i.59 
6.56±i.8i 
4.81 ±1.32 


5.78±i.59 
7.24±i.99 
7.88 ±2.17 
6.35±i-75 


E 


Tenth-acre plots . . 
Nine rod rows .... 
Five rod rows .... 
Four rod rows .... 


77.92 
75.82 
78.71 
72.31 


77-11 
77.75 
77-61 
78.01 


86.19 
85.40 
86.32 
84-36 


80.40 ±1.60 
79.66 ±1.61 
8o.88±i.5i 
78.23 ±1.92 


4.io±i.i3 
4.i4±i.i4 
3.87 ±1.07 
•4.92 ±1.35 


5.10 ±1.40 
5.20 ±1.43 
4.78 ±1.32 
6.28±i.73 



Table 8. — Comparison of the percentage increase in the yields of oats for each 
fertilizer treatment based on the mean yields of the checks at 
University Farm. 



Treatment. 


Tenth-acre plots. 


Increase in yield over the check as determined by harvesting 
the stated number of rod rows from each tenth acre. 


Nine rod rows. 


Five rod rows. 


Four rod rows. 




Percent. 


Percent. 


Percent. 


Percent. 


A 


5-58 


4.56 


3-02 


8.58 


B 


5-07 


6.37 


1.99 


14.66 


C 


6.12 


6,44 


1.66 


15-33 


D 


7-92 


4-93 


1.82 


11.26 


E 


4.02 


4.66 




14.99 



The percentage increase in yield for each treatment over the mean 
yield of the checks is given in Table 8, The moderate tho not sig- 



44 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



nificant increases in yield for all treatments are very similar for the 
plot and the 9-row methods. Still less increase in yield for the treat- 
ments is indicated by the 5-row method. By the 4-row method, B, C, 
and E gave significant increases in yield. At University Farm there 
was no significant increase due to the use of fertilizer treatment on 
oats. 

RESULTS WITH OATS AT THE DULUTH SUBSTATION. 

The yields for the three similarly treated plots with their constants 
are given in Table 9. The rod rows were removed from the plots at 
this location a week before the entire plots were harvested and while 

Table 9. — Comparison of yields and variability of Ligowa {Minnesota N 0. 281) 
oats grown at the Duluth substation under six different treatments as 
determined from triplicate tenth-acre plots and from g, $, and 4 
rod' rows removed from tenth-acre plots. 



Yield in bushels per 
acre for each of the 
triplicate plots. 



Tenth-acre plots 
Nine rod rows . . 
Five rod rows . . 
Four rod rows . . 

Tenth-acre plots 
Nine rod rows . . 
Five rod rows . . 
Four rod rows . . 

Tenth-acre plots 
Nine rod rows . . 
Five rod rows . . 
Four rod rows . . 

Tenth-acre plots 
Nine rod rows . . 
Five rod rows . . 
Four rod rows . . 

Tenth-acre plots 
Nine rod rows . . 
Five rod rows . . 
Four rod rows . . 

Tenth-acre plots 
Nine rod rows . . 
Five rod rows . . 
Four rod rows . . 



Means. 





60.70 


60.70 


6o.7o±o.oo 


62.15 


69.89 


64.64 


65.55i1.25 


61.41 


68.34 


60.92 


63.56i1.32 


63.16 


71.83 


69.38 


68.12 ±1.42 


39.00 


54-91 


69.36 


54.42 ±4.83 


77.84 


62.34 


69.13 


69.77 ±2.47 


80.96 


67.58 


70.41 


72.98 ±2.24 


74.04 


55.87 


67.61 


65.84i2.93 


52.03 


54.92 


69.37 


58.77 ±2.96 


86.59 


79.57 


72.34 


79.50i2.27 


86.45 


72.19 


51.76 


70.10 i2. 42 


86.87 


88.90 


73.27 


83.01 i2.70 


46.25 


66.48 


66.48 


59.74i3.72 


72.65 


88.81 


79.87 


8O.44i2.57 


77.14 


88.14 


76.80 


80.69 i2. 05 


67.13 


89.78 


83.81 


8O.24i3.73 


52.03 


54.92 


69.37 


58.77i2.96 


75.96 


75.90 


82.84 


78.23il.27 


77.85 


74.78 


90.41 


81.01 i2.63 


73.70 


77.38 


73.49 


74.86iO.7O 


60.70 


60.70 


66.48 


62.63 ii.o6 


78.48 


83.61 


58.35 


73.48 i4.24 


77.34 


81.24 


57.57 


72.05 i4.03 


80.00 


86.68 


59.40 


75.36i4.52 



Standaid 
deviations. 



0.00 iO. 00 

3.21 iO. 88 
3.39io.93 
3.65ii.oi 

12.40 i3.4i 
6.34±i.75 
5.76ii.59 
7.52i2.07 

7.59 ±2.09 
5.82ii.6o 

6.22 ii.71 
6.94ii.9i 

9.54±2.63 
6.61 ii. 82 
5.27ii.45 
9.59±2.64 



7.59i2.09 12.91 i3. 61 
3.26io.9o| 4.i7ii.i5 
6.76ii.86j 8.34i2.30 
1.79 io. 49 2.39 io. 66 



2.72 io. 75 
10.90 i3. 00 
10.36i2.85 



the oats were still slightly green. The third plot receiving treatment 
E is located on low ground and the oats was considerably more imma- 
ture at the time the rows were removed than it was on the other plots. 



ARNV AND GARBER: DETERMINING PLOT YIELDS. 



45 



In consequence the yield is low. This plot should have been allowed 
to stand for at least a week and another trip made to remove the 
rod rows from it. 

The first of the three check plots was injured between the time the 
rows were removed and the harvesting of the entire plots and the 
yield is therefore omitted. 

The percentage increases in yields are given in Table lo. No sig- 
nificant benefit is shown for the treatments by the yields secured from 
the entire plots. The 9-row method shows significant increases in 
yield from treatments B, C, D, and E. The 5-row method indicated 
that treatments C and D gave significant increases in yield. The 
4-row method indicates a significant increase in yield from treatment 
B and a near approach to it from treatment C. 



Table 10. — Comparison of the percentage increase in the yields of oats for each 
fertilizer treatment based on the mean yields of the checks at the 
Duluth substation. 



Treatment. 


Tenth-acre plots. 


Increase in yield over the check as determined by hai vesting 
the stated number of rod rows from tenth acre. 


Nine rod rows. 


Five rod rows. 


Four rod rows. 




Percent. 


Percent. 


Percent. 


Percent. 


A 




6.44 


14.82 




B 




21.28 


10.29 


21.84 


C 




22.72 


26.95 


17.79 


D 




19-34 


27.45 


9.89 


E 


3.18 


12.10 


13.36 


10.63 



Max Labor Requirements in Harvesting and Thrashing Plots and Rows. 

The labor requirements at University Farm in 191 7 for harvesting 
the entire tenth-acre plots as compared with removing 9 rod rows 
from the same tenth-acre plots varied with the condition of the straw. 
The oat crop stood up straight and, therefore, required less labor in 
harvesting than was necessary for the wheat, which was lodged badly. 
The amount of work that can be accomplished by a crew depends 
upon its personnel and on the organization and facilities. Other 
workers may find that the time for the operations as given is more 
than is needed or not enough. As is shown in Table 11, harvesting 
9 rod rows from a plot required approximately the same amount of 
man labor as harvesting the entire plot with a binder. Thrashing 
each of the 9 rod rows from a plot by beating the grain out by hand 
and weighing the product from each row separately required as much 
man labor as thrashing the product of the entire plot with a large 
machine. Using a small thrasher which delivers the grain free from 



46 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

straw and chaff would lower considerably the combined time given 
for thrashing and weighing in the row method. In the actual use of 
rod rows or small areas of other shape removed from plots to deter- 
mine yields, the product of the several small areas would be com- 
bined at harvest. In this way, the time required for harvesting, 
thrashing, and weighing would be materially reduced. 



Table it. — Comparison of the man-labor requirements of harvesting, thrashing 
and weighing grain from entire tenth-acre plots and from nine rod 
rows removed from the same plots. 



Operation. 


Necessary crew. 


Man hours per plot. 


Men. 


Horses. 


Grain standing. 


Grain lodged. 


Tenth-acre plots: 










Harvesting 


3 


2 


1. 00 


1.50 




10 


8 


1-33 


1-33 


Nine rod rows: 












I 





1. 00 


1.50 


Thrashing and weighing 


I 





1-33 


1.33 



Summary. 

1. In the direct comparison of yields to find the value of fertiHzer 
treatments, increases over the mean yield of the checks of 15.70 per- 
cent for the triplicate tenth-acre plots, 9.49 percent for the 9 rod rows, 
12.73 percent for the 5 rod rows, and 14.44 foi" the 4 rod rows re- 
moved from three similarly treated tenth-acre plots are, on the 
average, probably significant. For the work at the Duluth substa- 
tion, increases in yield over the checks of 32.40 percent for the tenth- 
acre plots and 12.34 percent, 16.56 percent, and 18.51 percent, re- 
spectively, for the 9, 5, and 4 rows removed from the plots seem nec- 
essary in order to be reasonably certain that the treatment is respon- 
sible for the differences. 

2. For the wheat at the Morris substation, a significant increase in 
yield for treatment B was indicated by the entire plots and by the 
9-row and 5-row methods and for treatment C by the 9 and 5 rod 
rows. Treatments D and E gave a significant increase in yield by each 
of the four methods. 

3. For the wheat at University Farm, moderate but not significant 
increase in yield is indicated for each treatment from harvesting the 
entire plot. From the yields of the 9, 5, and 4 rod rows, no increases 
due to the treatments are indicated. 

4. For the oats at University Farm, very similar but not significant 
increases in yields in percentage are indicated by harvesting the entire 
plots and by the 9 rod rows removed from them. The 5 rod rows in- 



ARNY AND GARBER : DETERMINING PLOT YIELDS. 



47 



dicate less and the 4 rod rows indicate more increase for the treat- 
ments than is indicated by the entire plots. 

5. At the Duluth substation no increases in yield due to treatments 
are indicated by harvesting the entire plots. The 9 rod rows indicate 
significant increases in yields for treatments B, C, D, and E and the 
5 rod rows for treatments C and D. The 4 rod rows indicate in- 
creased yield for treatment B. 

6. The man labor required to remove 9 rod rows from a tenth-acre 
plot, thrash these separately by hand, and weigh them is approximately 
the same as to harvest and thrash the entire plot. Using the rod-row 
method of ascertaining yields requires no horse labor and practically 
no machinery. 

Conclusions. 

From the evidence submitted, it seems fair to conclude that, for 
the conditions under which the work was done, 9 rod rows removed 
from tenth-acre plots gave practically as accurate indications of the 
value of fertilizer treatments as harvesting the product of the entire 
plots. 

This method of determining yields may be used to advantage in 
drilled grain in locations where facilities are lacking for harvesting 
and thrashing accurately the products of the entire areas. The amount 
of man labor required to determine yield by the plot and row methods 
is practically equal. 

Literature Cited. 

1. Arny, a. C, and Hayes, H. K. Experiments in field technic in plot tests. 

In U. S. Dept. Agr., Jour. Agr., Research, vol. 15, no. 4, p. 251-262. 1918. 

2. Hayes, H. K., and Arny, A. C. Experiments in field technic in rod row 

tests. In U. S. Dept. Agr., Jour. Agr. Research, vol. 11, no. 9, p. 399- 
419. 191 7. 

3. McCall, A. G. A new method of harvesting small grain and grass plots. 

In Jour. Amer. Soc. Agron., 9: 138-140. 1917. 
4 Wood, T. B., and Stratton, F. J. M. The interpretation of experimental 
results. In Jour. Agr. Sci. 3: 415^440. 1910. 



48 



AGRONOMIC AFFAIRS. 



AGRONOMIC AFFAIRS. 

OUTLOOK FOR 1919. 

With the close of the war will come abundant opportunity for ex- 
tension of agronomic work and experimentation, necessitating the 
employment of many additional men in agronomic lines. This ex- 
tension of agronomic endeavor widens the field for the American 
Society of Agronomy, and to our Society there should come a large 
growth in membership and power during the next few years. Each 
of the present members should make a special effort to bring the 
Society to the attention of agronomic workers in their institution, 
for every member added to our list enables your officers to render a 
little more service to all by printing a larger and better journal. The 
editor of the Journal of the American Society of Agronomy 
bespeaks your active cooperation for 1919 in bringing the Society 
and its publication to the position each should occupy among Amer- 
ican scientific organizations and journals. This cooperation can be 
given along three lines, (i) by sending your own membership dues 
for the year promptly to the secretary-treasurer, (2) by urging other 
workers to join, and (3) by sending papers to the editor for publica- 
tion. Let us all get together and make 1919 by far our best year! 

DELAY IN DECEMBER NUMBER. 

Because of the postponement of the meetings of agricultural col- 
lege and experiment stations workers and, with them, the meeting 
of the American Society of Agronomy, the publication of the De- 
cember issue of the Journal has been greatly delayed. This number 
is now in press, however, and will be ready for mailing soon. It will 
contain the president's annual address, the reports of officers and 
committees, minutes of the annual meeting, and title pages and index 
for A'olume 10. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. February, 191 9. No. 2 



NITROGEN RELATIONS OF CERTAIN CROP PLANTS WHEN 
GROWN ALONE AND IN ASSOCIATION.^ 

R. C. Wright. 

A knowledge of the behavior of leguminous and nonleguminous 
plants when grown in association is of practical and also of consider- 
able scientific interest. The investigations recorded here were 
prompted by the comparatively recent work in this country reported 
principally by Lyon and Bizzell, Lipman, and Westgate and Oakley. 
An examination of the results of these workers shows that very often 
the nitrogen composition of a nonlegume is increased when grown 
with a legume, tho this is not always the case. Apparently much 
depends upon the climatic and soil conditions under which legume- 
nonlegume mixtures are grown as well as upon the composition of the 
mixtures themselves.- Westgate and Oakley incorporate a fortunate 
note of warning in their conclusion :^ 

The data . . . would seem to indicate that the phenomenon of increased pro- 
tein content in the nonlegume by reason of its association with the legume is 
not so universally true as to make it safe to advocate the method unreservedly 
as a means of increasing the production of protein upon the farms of this 
country. 

1 These investigations were conducted under the direction of Karl F. Keller- 
man, Bureau of Plant Industry, U. S. Department of Agriculture. The paper 
was received for publication September 12, 1918. 

~ Kellerman, K. F., and Wright, R. Claude. Mutual influence of certain crops 
in relation to nitrogen. In Jour. Amer. Soc. Agron., v. 6, nos. 4-5, p. 204-210. 
1914. 

3 Westgate, J. M., and Oakley, R. A. Percentage of protein in nonlegumes 
and legumes when grown alone and in association in field mixtures. In Jour. 
Amer. Soc. Agron., v. 6, nos. 4-5, p. 210-215. 1914. 

49 



50 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The author has noted a rather reckless tendency of some popular 
writers to recommend the growing of mixtures of nonlegumes 
and legumes which have not been carefully tested. " One such 
writer advocated the growing of corn and soybeans together, stat- 
ing that besides increasing the protein value of the corn the beans 
would fix more than enough nitrogen in the soil to account for that 
removed in the growth of both corn and beans. It seemed to the 
writer that, as much of the work already reported upon has been 
conducted in the field, possibly more investigations should be made 
under strictly control conditions, thus insuring against nonuniformity 
of soil. The experiments here reported were conducted at the Ar- 
lington Farm of the United States Department of Agriculture during 
1914 and 1915. The test crops were grown in galvanized corrugated 
iron buckets 15 inches in diameter by 13 inches deep. These buckets 
hold from 100 to 120 pounds of soil, depending on its character. All 
were housed in a cage built of i-inch pipe covered with wire netting. 
The buckets were watered to weight daily with distilled water. 
Further description of the construction of the cage and the handling 
of the containers is given in another paper.* Plate i shows the 
manner of growing the crops in these experiments. 

The soil used was screened, shoveled over several times on a cement 
floor, and equal quantities then weighed into the buckets. Leguminous 
and nonleguminous crops were grown both alone and in combina- 
tion. When grown in combination half as many plants of each crop 
were grown in each bucket as when grown alone. After reaching 
maturity each crop, regardless of the accompanying crop, was har- 
vested close to the surface of the soil and dried, weighed, and ground 
fine for analysis of total nitrogen. When all were harvested the roots 
were removed from the soil in each bucket and after being dried and 
ground were returned and thoroly mixed with the soil to allow more 
uniform sampling. Samples of soil were then removed and air- 
dried for nitrogen analysis. 

All nitrogen results reported constitute the average of two closely 
agreeing determinations on i-gm. samples of crops and lo-gm. samples 
of soil. Determinations on crop samples were made by the Gunning 
method, on soil samples by the Kjeldahl-Gunning-Jodlbauer method, 
using with both methods the sulfate mixture recommended by Lipman 
and Sharp. ^ Nitrates were determined in duplicate by a modifica- 

4 Wright, R. Claude. Growing plants in large containers under control con- 
ditions. In Jour. Amer. Soc. Agron., v. 8, no. 2, p. 113-116. 1916, 

5 Lipman, C. B., and Sharp, L. T. Toxic effects of " alkali salts " in soils on 
soil bacteria. III. Nitrogen fixation. In Centr. Bakt., Abt. 2, 35 : 648. 1912. 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



51 



tion of the Ulsch method, reduction taking place over night in acidified 
soil extracts in presence of iron dust. The operation may briefly be 
described as follows: One hundred grams air-dry soil is shaken at 
frequent intervals for a half hour with 300 c.c. of distilled water and 
about a gram of calcium oxide. The extract is then filtered, meas- 
ured, and acidulated with 3 c.c. sulfuric acid; about 2 gm. of iron 
dust are added and reduction allowed to take place over night in the 
cold. Approximately 8 gm. of magnesium oxide are then added and 
ammonia distilled off in the usual way. 

Experiments in 1914. 

In 1914 the soil used was a clay loam which had been composted 
with manure and left in a pile for several years. A quantity of this 
soil was limed and thoroly stirred, after which equal quantities repre- 
senting 45 kg. when brought to the optimum moisture condition were 
weighed into the buckets. The crops grown this season were spring 
oats, spring barley, spring rye, and dwarf kafir, each grown in associa- 
tion with hairy vetch, field peas, and red clover. Corn was also 
grown both with oats and pearl millet. Each of these crops named 
was also grown alone. All combinations were planted in duplicate 
buckets, while quadruplicates were planted to each variety when grown 
alone, as these also served in another investigation carried on simul- 
taneously. 

Table i shows the yields in dry matter of all the crops both when 
grown alone and when grown in association. These will be considered 
in conjunction with Table 2 and figure 3, showing the average yields 
in weight of nitrogen. In examining these and subsequent results 
one should bear in mind that, as previously stated, when grown in 
combinations half as many plants of each crop was used as when 
grown alone, thus assuring more equal conditions for each crop than 
if the same number of plants of each variety were grown in combina- 
tion as when grown alone. Considering the results as a whole, the 
nonlegumes in most cases when grown in combination with legumes 
made nearly as much dry matter and weight of nitrogen as when 
grown alone. The legumes used, being generally less vigorous grow- 
ers, possibly suffered at the expense of the nonlegumes by the as- 
sociation. 

Taking the results in order, barley in combination with hairy vetch, 
field peas, and red clover made practically as much dry matter as 
when grown alone. Vetch and clover in these combinations also 
made nearly as much dry matter as when grown alone. These two 



52 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



combinations with barley seemed to be particularly favorable, espe- 
cially barley and clover. The total yield of dry matter from the 
barley and vetch combination equaled 159.5 gm., while that from 
barley and clover was 181 gm. Barley alone yielded 118. 2 gm. ; vetch, 
77.5 gm. ; and clover 94.0 gm. 



Table i. — Dry weights in grams of various crops when grown alone and in 
association with other crops.^ 



Crop. 


Grown 
alone. 


Grown in association with — 


Vetch. 


Field peas. 


Red clover. 


Corn. 


Weight 
of crop. 


Com- 
bined 
weight.* 


Weight 
of crop. 


Com- 
bined 
weight.* 


Weight 
of crop. 


Com- 
bined 
weight,* 


Weight 
of crop. 


Com- 
bined 
weight.* 


Barley . . . 


118. 2 


105-3 


159-5 


II5-4 


116. 7 


115.0 


181.O 






Rye 


43-5 


38.7 


120. 1 


21.9 


29.0 


30.7 


108.4 






Oats 


145.6 


123.5 


126.2 


136.3 


140.8 


128.5 


193.7 


61.0 


265.6 


Kafir .... 


357-0 


298.0 


330.9 


296.0 


308.8 


266.3 


288.6 






Millet . . . 


308.5 














84.4 


317-5 





Grown 




Giown in association with — 




Crop. 












alone. 










Pearl millet. 




Barley. 


Rye. 


Oats. 


Kafir. 


Vetch 


77-5 


54-2 


81.4 


2.7 


32.9 






49.3 


'=1.3 


7-1 


4-5 


12.8 




Red clover 


94.0 


66.0 


77-7 


65.2 


22.3 




Corn 


320.9 






204.6 




233-1 



" Weights of crops grown alone are averages of yields from four cans and 
weights of crops grown in association are averages of duplicates, except as 
noted. 

^ Combined weights of associated crops. 
^ Yield from one can only. 

The barley-vetch and barley-clover combinations also yeilded more 
grams of nitrogen than either grown alone. Barley and vetch equaled 
3.65 gm. and barley and clover 3.89 gm., as against 2.16 gm. for 
barley alone, 2.18 gm. for vetch alone, and 2.45 gm. for clover alone. 
The growth of peas with barley was almost negligible, while barley 
in this combination practically equaled that when grown alone. When 
peas and barley were grown together the yield in nitrogen was only 
slightly greater than that from barley alone. 

A comparative study of the amount of nitrogen remaining in the 
soil after these crops were grown as shown in figure 3 is of interest. 
In both the barley-vetch and barley-clover combinations, while the 
yield in grams of nitrogen is considerably larger than any of these 
crops grown alone, the amount of nitrogen left in the soil is also 
greater. In other words, these com'binations remove less nitrogen 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



53 



tf/tTROGfrt //y SO/L 



J 4 S ^: fc £! !3 S 



Luminous c/fops. 



6/f/}/75 or /Y/rpocs/v 
'$ t t ^ "a 



VETCH 





RID ClOl^£M 

^yc a 

PCD CLOy£R 



OPTS a 



OPTS 
r/ELDPF/iS 
OPTS A 

r/no pm 



OPTS 

pro cLo^i 
o/fr<s a 



Nl l lll l iiill 




Fig. 3. Grams of nitrogen remaining in the soil after harvest and that recov- 
ered in the crops when grown both alone and in association. 



54 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



from the soil than any of their components when grown alone and 
at the same time yield almost double the weight of nitrogen, the 
increased nitrogen in the yield having apparently been gained from 
the atmosphere through bacterial nitrogen fixation. With the barley- 
pea combination considerably more nitrogen was removed from the 
soil than was recovered, showing a distinct loss. 



Table 2. — Weight in grams of nitrogen in crops when grown alone and in 

association.^ 











Grown in association with- 










Grown 


Vetch. 


Field peas. 


Red clover. 


Corn. 


Crop, 


















alone. 


c . 








c . 




c . 

4) 0, 








u 












ho 
u 


li 
















bo 
E 'v 


u 










> 
U ^ 




U ^ 


g.s. 


U ^ 






Barley 


2.i6=to.o5 


2.03=1=0.28 


3.65 


2.23=t0.0I 


2.27 


2.07 =1=0.04 


3.89 






Rye 


^83=±= .04 


.70=1= .05 


3-13 


.41 =t .14 


.60 


.56=1= .08 


2.60 






Oats 


2.44 =t ' .02 


2.39 =t= .07 


2.44 


2.74=1= .03 


2.84 


2.38=1= .14 


4.20 


0.78=1=0.04 


2.08 


Kafir 


2.88± .13 


2.72=1= .32 


3-72 


2.77 ='= .03 


3.01 


2.47 =fc .19 


3-00 






Millet 


2.10='= .03 














.59=^ .08 


2.00 



Crop. 


Grown 
alone. 


Grown in association with — 


Barley. 


Rye. 


Oats. 


Kafir. 


Pearl millet. 


Vetch 

Red clover 


2.18=1=0.15 
I.32=t .25 

2.45^ -05 
2.15=1= .08 


1.62 =1=0.25 
'^.04 

1.82=1= .13 


2.43=1=0.19 
.19=1= .02 
2.04=1= .21 


0.05=^0.02 
.10=1= .05 
1.82=1= .14 
1.30=1= .06 


i.oo =1=0.18 

.24=1= .08 
.53=^ .19 


1.41=1=0.13 



" Results reported for crops grown alone are averages of yields from four 
cans and those of associations are averages of yields from two cans, except as 



noted. The formula used in computing averages was J?w=: 0.845 • 

nVn — I 

Rm = probable error of the mean, Sc? — sum of the departures, n = number of 
determinations. 

^ Combined weight of nitrogen in the two constituents. 

^ Average of three samples. 

^ One sample only. 

Considering next the combinations with rye, we find that the rye- 
vetch combination gave the greatest quantity of dry matter, 120 gm., 
followed by the rye-clover combination with 108.4 gn^v as against 
43.5 gm. for rye, 77.5 gm. for vetch, and 94.0 gm. for clover when 
each was grown alone. In the rye-pea combination the dry matter 
from each component was materially reduced as compared with these 
when grown alone. The yield of nitrogen in the rye-vetch combina- 
tion was somewhat greater than when either was grown alone. In 
the rye-pea combination the yield of nitrogen was less than when 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



55 



either was grown alone, and at the same time more nitrogen was 
removed from the soil, showing a loss similar to that in the barley- 
pea combination. The rye-clover combination also shows a loss in 
soil nitrogen not recovered in the crops grown. This combination 
removed 3.25 gm. more nitrogen from the soil than the rye crop 
alone and only 2.60 gm. of this was recovered in the combination 
crop. In the light of our present knowledge this loss is unaccount- 
able. It can not possibly be due altogether to error in analysis, as 
it occurs in several cases and all determinations were made in dupli- 
cate on at least two parallel samples. 

The yield of dry matter in vetch and peas when grown with oats 
was almost negligible, while that from oats in the combinations was 
almost as great as when oats were grown alone. In neither com- 
bination did the yield in dry matter equal that when oats were grown 
alone. The dry matter from the oat-clover combination was con- 
siderably in excess of either grown alone, amounting to 193.7 
against 145.6 gm. and 94.0 gm. for oats and clover respectively when 
grown alone. The yield of nitrogen from oats and vetch when grown 
separately was practically the same; however, when grown in com- 
bination the nitrogen from vetch was almost nil. The combined 
weight of nitrogen was the same as that from oats alone, but the 
amount of nitrogen left in the soil under this combination was 0.6 
gm. greater than that left by oats alone. The nitrogen in oats when 
grown with peas was greater than when grown alone, being 2.49 gm. 
when grown alone and 2.74 gm. when with peas. On the other hand, 
nitrogen in peas when grown alone was 1.32 gm. and was reduced 
to o.io gm. when grown with oats. As in the case of oats and vetch, 
this combination of oats and peas left more nitrogen in the soil than 
oats alone, altho the combined crop (in fact, the oats in the combina- 
tion crop) contained more nitrogen than when oats were grown alone. 
In the oat-clover combination the nitrogen in the oats was practically 
the same as in oats grown alone. The combined weight of nitrogen 
was 4.20 gm. Very little more nitrogen w^as removed from the 
soil under the combination crop than under either of the single crops, 
altho the combination crop yielded nearly double the amount of 
nitrogen. 

The combinations in which kafir entered did not yield as much dry 
matter as kafir grown alone. This possibly was due to some extent 
to the fact that the legumes used in these experiments normally yielded 
so much less gross dry matter than the kafir that when grown in 
association they were not able to make up for the deficiency caused 
by cutting the number of kafir plants in half. However, the kafir 



56 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

was benefited at the expense of the legumes by the association, as the 
gross yields of dry matter were not very materially reduced as com- 
pared with this crop grown alone. On the other hand, the gross 
yields from the legumes were reduced more than half. The combined 
yields of nitrogen from these associations was greater than when any 
of the crops were grown alone. 

When oats or pearl millet is grown with corn the yield of dry 
matter in these crops is greatly reduced, but the yield from corn is not 
proportionately reduced. The yield of nitrogen was less in both 
combinations of millet and oats with corn than in any of these grown 
alone. Under the corn-millet combination practically as much nitro- 
gen was removed from the soil and not recovered in the crop as under 
rye and clover. In this case more was removed than by either corn 
or millet alone and the amount recovered in the combined crop was 
not equal to this difference. 



Table 3. — Percentage of nitrogen in various crops when grown alone and in 
association with other ^crops.^ 



Crop. 


Grown alone. 


Grown in association with — 


Vetch. 


Field peas. 


Red clover. 


Corn. 


Barley 

Rye 

Oats 

Kafir 


1.84=^0.03 
^I.87=i= .01 

i.68=«= .01 
.8i=t= .02 
.68=i= .01 


1.92 =1=0.02 
1.82=1= .91 
1.94 =t .04 
.90=1= .04 


I.94±0.05 
1.90=1= .01 
2.01=1= .01 

.94=1= .08 


I.80±o.03 
1.82 =t .02 
1.85=1= .00 
.93=^ .03 


I.29=t0.02 
.69=1= .00 


Crop. 


Grown alone. 


Grown in association with — 


Barley. 


Rye. 


Oats. 


Kafir. 


Pearl millet. 


Vetch 

Field peas. . . 
Red clover. . 


2.82±0.02 
2.76=±= .07 

2.61=1= .03 
.66 ± .01 


2.97 =to.I7 
^^2.85 

2.77=1= .10 


2.99=1=0.00 
2.65=1= .07 
2.64=t: .04 


1.91 =to.io 

2.24=1= .01 

2.79^ -03 

.63=1= .01 


3.10=1=0.14 
1.94=1= .06 
2.44=1= .11 


0.60=to.02 



* Data for crops grown alone are averages of results from four cans, and 
those for crops grown in association are averages of duplicates, except as noted. 
^ Average of three samples. 
^ One sample only. 



Table 3 and figure 4 show the percentage of nitrogen in the various 
crops grown alone in comparison with that when they are grown in 
association. In the barley-vetch and barley-pea combinations the per- 
centage of nitrogen in both the barley and the legume was increased. 
When barley and clover was grown together the percentage of nitro- 
gen in barley was decreased and in clover it was increased. In the 
rye-vetch combination the percentage of nitrogen was decreased in 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



57 



rye and increased in vetch. In the rye-pea combination the per- 
centage in rye was very sHghtly increased and that in peas decreased. 
In rye and clover the percentage in rye was again decreased and in 
clover slightly increased. In the oat-vetch combination the percentage 
of nitrogen was increased in oats and materially decreased in vetch. 
Likewise in oats and peas the percentage of nitrogen increased in oats 
and decreased in peas. In oats and clover the nitrogen percentage 
is increased in both constitutents. In the kafir-vetch combination 
both constituents increased in nitrogen percentage. The nitrogen 
percentage in kafir increased when grown with peas or clover, while it 
decreased in the legumes. 

It will be noticed in figure 3, on comparing the nitrogen in the 
dry checks or original soil with that in the soil after growing the 
various crops, that in only a few cases was the nitrogen removed by 
a given crop recovered in that crop. In some of the combinations 
more nitrogen was recovered than was removed from the soil. In 
some cases, especially with barley and peas, rye and peas, rye and 
clover, and corn and millet, the loss in nitrogen was quite serious. 
The question of this loss of nitrogen will be dealt with at length in a 
later paper. 

In conclusion, nine representative field crops were grown alone 
and in certain combinations in large galvanized iron buckets holding 
45 kg. moist soil. When two species of plants were grown in asso- 
ciation, half the number of plants of each was used as when grown 
alone. Crops were grown to maturity and harvested close to the 
surface of the soil. Roots were included with the soil. There was 
a distinct loss of nitrogen in the following combinations : Barley and 
peas, rye and peas, rye and clover, and corn and millet. There was a 
distinct gain in nitrogen with barley and vetch, barley and clover, oats 
and peas, oats and clover, and kafir and vetch. In general, when 
barley and vetch, barley and clover, oats and vetch, oats and peas, and 
kafir and vetch were grown together, altho more dry matter and 
nitrogen were produced, not so much nitrogen was removed from the 
soil as when these crops were grown alone. 

Barley gained in percentage of nitrogen with vetch and peas while 
it lost with clover. Rye lost slightly with vetch and clover and 
gained slightly with peas. Both oats and kafir gained with vetch, 
peas, and clover. Simultaneously, vetch gained in percentage of 
nitrogen with barley, rye, and kafir, but lost with oats. Field peas 
gained with barley but lost with rye, oats, and kafir. Red clover 
gained with barley, rye, and oats but lost with kafir. Corn when 



58 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 




Pf^ce/vT OF r//r^oGS/y 

? ? ? .0 ^ ^ ^ £: 





P/fjLDPOS 



OPTS 
OPZS » 



Fig. 4. Percentage of nitrogen in the crops when grown alone and in association. 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



59 



grown both with millet and oats lost in percentage of nitrogen, while 
millet gained very slightly and oats lost materially. 

Experiments in 1915. 
The next season's work (1915) was planned more to observe the 
comparative results of a few combinations in different types of soil 
rather than the results of a large number of combinations. Con- 
sequently only three nonlegumes and two legumes were grown, viz. : 
Spring oats, spring barley, kafir, soybeans, and purple vetch. These 
combinations allow comparisons between the growth of a nonlegume 
in association with a strong, vigorous-growing legume like the soy- 
bean, which is likely to compete very actively for plant food, and a 
weaker-growing legume like the vetch. We were unfortunate in the 
selection of the variety of oats (Sixty-Day), as it made only slight 
growth, maturing when the plants were quite small. These crops 
were grown in triplicate in three parallel series on the following types 
of soil: Semiarid, a coarse gravelly virgin loam from near Riverside, 
Cal. ; Great Plains, a heavy black virgin loam from near Manhattan, 
Kans. ; and eastern humid, a practically virgin clay loam from near 
Arlington, Va. In all other respects this experiment was handled the 
same as in 1914. 



Table 4. — Dry weight in grams of crops grown alone and in association in Cali- 
fornia, Kansas, and Virginia soil at Arlington Farm, Va.^ 

NONLEGUMES. 



Association. 


Grown in Cal. soil. 


Grown 


in Kansas soil. 


Grown in Va. soil. 


Oats. 


Barley. 


Kafir. 


Oats. 


Barley. 


Kafir, 


Oate. 


Barley. 


Kafir. 


Grown alone 


36.5 


295 


65-7 


30.2 


26.0 


99 


12.7 


10.8 


II7.7 




23.0 


33-2 


40.8 


16.8 


15-2 


40.8 


6.2 


10.8 


49 -S 


With vetch 


27.0 


20.2 


38.7 


21.5 


15.2 


100.5 


10.7 


9-3 


72.7 



LEGUMES. 



Association. 


Grown in Cal. soil. 


Grown in Kansas soil. 


Grown in Va. soil. 


Soybeans. 


Vetch. 


Soybeans. 


Vetch. 


Soyb 


eans.j Ve 


ch. 


"o 


.s - 

6 ' 




M £ 
•53 u 


C V 

^ 

U 





V 

J2 bt) 

g-s 

U 





. 
.S.S 

^ be 




£ a 
.5*2 

„o 


Combined 
weight.6 

Weight of 
crop. 


bx> 
B 'C 
^ 
U ' 


With barley 

With kafir 


127-3 
51.2 
53 
52.3 


74.2 
86.2 

93-1 


13.8 
12.7 
6.7 

10. 


39-7 
26.9 
48.7 


59-8 
38.5 
31-7 
49.8 


55-3 
46.9 
90.6 


7.2 
9.3 
7.7 
4.2 


30.8 
22.9 
104.7 


63-7 
44-3 
40.5 
45.5 


1 

7-7 

50.51 4-0 
51-31 2.8 
95 oi 6.2 


14-7 
12. 1 
78.9 



"All data reported are average yields of three cans. 

* Combined weight of legume and nonlegume grown in association. 



6o JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

In Table 4 the weights of dry matter yielded by the crops grown 
alone and in association in the three soils are shown. No attempt 
will be made to draw comparisons between the yield of the different 
soils from the standpoint of determining their relative value or pro- 
ductiveness, as this obviously is not the purpose of the experiment. 
In all three soils the oat-soybean and barley-soybean combinations 
yielded less dry matter and weight of nitrogen than soybeans alone, 
due to the reduction in number of plants overbalancing any possible 
benefit to the remaining plants. 

In California soil the yield of oats in association with soybeans was 
only slightly reduced, while that of soybeans was reduced more than 
half. The oat-vetch combination yielded a very slight increase over 
either grown alone in all the soils. The barley-soybean combination 
also showed a decreased yield as compared with soybeans alone. In 
California soil again the yield of beans was reduced more than half, 
but the yield of barley was slightly increased. In Kansas soil the 
yield of both barley and beans was reduced by apparently half, while 
in Virginia soil and yield of barley in the combination was the same 
as when grown alone and the yield of beans was reduced by about 
one-third. 

In California soil the yield of barley with vetch was somewhat re- 
duced, while the vetch was reduced by about half. The combination 
gave a yield of dry matter less than from barley alone. In Kansas 
soil the yield of barley was less in the combination and the yield of 
the combination was less than barley alone. In Virginia soil the 
yield from the combination was practically the same as from barley 
alone. The yield of vetch was less than half that when grown alone. 

In the kafir-soybean combination in California soil the yield was less 
than from beans alone and greater than from kafir alone. However, 
while the yield of kafir was about one-third less than when grown 
alone, the yield of beans was over half less. In Kansas soil the yield 
of the combination was less than kafir alone and greater than soy- 
beans alone. In this soil the yield of kafir in the combination was 
reduced more than half and the yield of beans less than one-third. 
In Virginia soil practically the same relations resulted in this com- 
bination as in Kansas soil. With the kafir-vetch combination prac- 
tically the same relations resulted in CaHfornia and Virginia soils. 
The combination yielded considerably more than vetch alone and 
less than kafir alone, while the yield of eaxh in the combination was 
about one-third that when grown alone. In Kansas soil the yield 
from the combination was greater than that of either of the con- 
stituents grown alone. 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



6i 



Considering further relations between the various leguminous and 
nonleguminous crops in the different soils, it will be observed that in 
California soil oats when grown with purple vetch yields less dry 
matter than when grown with soybeans, a much larger and more 
vigorous crop which might be expected to compete more actively for 
plant food if plant food alone were the only controlling factor to be 
considered. Likewise barley and kafir produced less dry matter when 
grown with vetch. On the other hand, vetch made a better growth 
with oats than with either barley or kafir. These relations did not 
hold in Kansas soil. Here oats made a little better growth with 
vetch, barley made practically the same growth with beans and vetch, 
and kafir made almost double the growth with vetch that it did with 
beans. Soybeans with kafir made a better growth than with either 
of the less vigorous oats and barley. In Virginia soil these relations 
are not marked enough to call for special comment. 



Table 5. — Total nitrogen (in grams) in crops grown alone and in association in 
California, Kansas, and Virginia soil at Arlington Farm, Va.^ 



Soil and associa- 
tion. 


Nonlegumes. 


Legumes. 


Oats. 


Barley. 




afi 


r. 


Soybeans, 


Vetch. 


Nitrogen in 
crop. 


Com- 
bined 
weight.* 


Nitrogen in 
crop. 


Com- 
bined 
weight.* 


California soil: 






























Grown alone . . 


0.34 




3.00 


0.29 ± 


3.01 


0.38 




0.02 


3.67 ±0.04 




o.35=^c 


.07 




With soybeans 


.24 




.02 


.31=^ 


.01 


'•34 


















With vetch. . . 


.29 




.01 


.22 =^ 


.01 


.30 




.02 














With oats. . . . 


















1.74^ 


.16 


1.98 


.34^ 


•05 


0.63 


With barley. . 


















1.77=^ 


•05 


2.08 


<^.I9 




•41 


With kafir. . . . 


















i.66± 


.12 


2.00 


.23^ 


.04 


•53 


Kansas soil : 






























Grown alone . . 


•55 


± 


.12 


■53^ 


.07 


•94 




.14 


1.67 ± 


.14 




.2I± 


.01 




With soybeans 


.33 




.07 


.30 ± 


.07 


•38 




.07 














With vetch. . . 


•45 




.01 


.32^ 


.07 


1. 01 




•03 














With oats. . . . 


















1.22 =•= 


•13 


1^55 


.26± 


.01 


•71 


With barley . . 


















1.02 ± 


.29 


1.32 


.2I=t= 


•05 


•53 


With kafir 


















i.30± 


.20 


1.68 


.09 ± 


.01 


1. 10 


Virginia soil: 






























Grown alone . . 


•30 




.02 


.32^ 


.01 


1. 1 7 




.06 


1.88 ± 


.07 




.26± 


.08 




With soybeans 


.12 




.01 


.24± 


.01 


•51 




.01 














With vetch . . . 


.26 




•03 


.27 ± 


•05 


.89 




.08 














With oats. . . . 


















1-34=^ 




1.46 


.II± 


.02 


•37 


With barley. . 


















1.22 =t 


.06 


1.46 


".07 




•34 


With kafir 


















1.09 ± 


.04 


1.60 


.I9± 


.02 


1.08 



° Data are averages of yields from triplicate cans, except as noted. 
^ Combined weight of associated legume and nonlegume. 
^ Average of two samples only. 



62 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Considering next the yield of nitrogen expressed in terms of grams 
of nitrogen yielded in each crop grown alone and in association, these 
results are shown in Table 5 and figure 5. 




^ I III 



^1^ 



I 

Hi! 

I ill 




I III 





















u 




























































































































1/ 




5 ^ « s; 












V\ 




















































ii 1 
1 s 


s 11 



10 

d 



In California soil the relations of the combinations of soybeans with 
oats, barley, and kafir were much the same. Beans grown alone 
yielded considerably more nitrogen than any of the others grown 
alone. The weight of nitrogen yielded by the combinations was in 
every case greater than from the nonlegume grown alone and less 



WRIGHT: NITROGEN RELATIONS OF CROPS. 



63 



than from soybeans alone. At the same time more nitrogen was 
removed from the soil than by soybeans grown alone or by oats and 
kafir alone. The combination crops where purple vetch was grown 
with oats, barley, or kafir yielded somewhat more nitrogen than any 
of these grown alone. The oat-vetch and kafir-vetch combinations 
removed less nitrogen from the soil than any constituents grown sepa- 
rately. In the case of the barley-vetch combination more nitrogen 
was removed from the soil than by either constituent grown alone. 
While practically all the nitrogen removed from the soil by the growth 
of the combinations was recovered in the crop produced it is quite 
noticeable how much nitrogen was removed from the soil and not 
recovered by the crop in the case of oats, barley, kafir, and vetch 
grown alone. 

In Kansas soil relations entirely different from those in California 
soil seemed to hold. The yield of nitrogen from the combinations 
of soybeans with oats, barley, and kafir was greater than from any 
of the nonlegumes and practically the same as from soybeans grown 
alone. At the same time less nitrogen was removed from the soil 
under these combinations than under any of the separately grown 
crops. Soybeans in this soil removed considerably more nitrogen 
than was recovered in the crop. The same was true of oats, barley, 
and kafir, but not to such a great extent as with soybeans or to such 
an extent as in California soil. There was a gain in nitrogen over 
that removed from the soil under the oats-soybean and kafir-soybean 
combinations. After growing vetch there still appeared to be a 
somewhat greater amount of nitrogen in the soil than in the original 
soil as represented by the dry check. Oats and vetch together yielded 
a slight increase in nitrogen over oats alone, altho no more nitrogen 
was removed from the soil. Barley and vetch together yielded the 
same amount of nitrogen as barley alone, but did not remove nearly 
as much nitrogen from the soil. Kafir and vetch together yielded 
more nitrogen than kafir alone and yet did not remove nearly as much 
nitrogen from the soil. 

In Virginia soil soybeans in combination with oats, barley, and 
kafir yielded more nitrogen than any of these grown alone, but not 
so much as soybeans grown alone. The soybean-oat combination 
removed but little more nitrogen from the soil than oats alone and 
not so much nitrogen as soybeans alone. The soybean-barley com- 
bination removed considerably more nitrogen than barley alone and 
somewhat more than soybeans alone. The kafir-soybean combination 
removed about the same amount of nitrogen as soybeans alone and 
not so much as kafir alone. The oat-vetch and barley-vetch combina- 



64 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

tion yielded a trifle more nitrogen than either alone. Oats-vetch 
removed a little more nitrogen from the soil than vetch alone and 
not so much as oats. Barley-vetch removed more nitrogen than either 
alone. Kafir-vetch did not remove as much nitrogen as kafir alone, 
but considerably more than vetch. 

The last relations to be considered are the percentages of nitrogen 
in the different crops grown alone and in association. These are 
shown in Table 6 and figure 6. 



Table 6. — Percentage of nitrogen in crops grown alone and in association in 
California, Kansas, and Virginia soil at Arlington Farm, VaJ^ 



Soil and association. 


Nonlegumes. 


Legumes. 


Oats. 


Barley. 


Kafi 


r. 


Soybeans. 


Vetch. 


California soil: 






















Grown alone 


0.94=1=0.01 


0.99=1=0.02 


0.58=1=0.01 


2.89=1=0.06 


2.47 =t 


O.II 


With soybeans 


1.09 =t= 


.10 


.94=^ 


.04 


^64 












With vetch 


1.07 =1= 


.04 


1.09 ± 


.02 


.78 ± 


.08 
























3-43^ 


.07 


2.66 =t 


.02 


With barley 














3.33=^ 


.02 


^2.45 




With kafir 














3-17=^ 


.04 


2.30=t 


.09 


Kansas soil: 






















Grown alone 


i.78=t 


.11 


2.06 =t 


.05 


•95 ± 


.09 


2.81 =t 


•05 


2.88 =±= 


.11 


With soybeans 


1-93=^ 


,02 


1.98 =t 


.07 


•93=^ 


.01 










With vetch 


2.08=1= 


.07 


2.03=1= 


.14 


1.03=1= 


.10 










With oats 














3-20± 


.08 


2.80 =±= 


.08 


With barley 














3.27=^ 


.07 


2.73=^ 


•05 


With kafir 














2.52=1= 


.14 


2.i8=t 


•05 


Virginia soil: 






















Grown alone 


2.37=^ 


.05 


2.92 =t 


.08 


1.00=1= 


.07 


2.96=1= 


.08 


3-35=^ 


.16 


With soybeans 


2.00=*= 


.03 


2.21 =±= 


.08 


1.06 ± 


.04 










With vetch 


2.43=^ 


.07 


2.92 =t 


.04 


1.27=1= 


.10 










With oats 




3-o6± 


.10 


2.69 =t 


.09 


With barley 














3-04=*= 


.16 


^2.39 




With kafir 














2.40 ± 


.04 


3-05=^ 


.10 



« Data are averages of yields from triplicate cans, except as noted. 
^ Average of two samples only. 



Considering first the results with California soil, the percentage of 
nitrogen in oats was increased both when grown with soybeans and 
vetch. Simultaneously, the nitrogen percentage was increased in both 
soybeans and vetch by the association. The percentage of nitrogen 
in barley was somewhat decreased when grown with soybeans, while 
that in the soybeans was increased. There was an increase in barley 
with vetch, while in vetch there was a slight decrease. When kafir 
was grown with soybeans and vetch the percentage of nitrogen was 
increased by the association, while in soybeans there was an increase 
and in vetch there was a decrease. In Kansas soil the percentage 



WRIGHT : NITROGEN RELATIONS OF CROPS. 



65 



of nitrogen was increased in oats when grown with soybeans and 
especially with vetch. It also was increased in soybeans when grown 
with oats, but was decreased in vetch. With barley the percentage 




of nitrogen was reduced when grown both with soybeans and vetch, 
while that of soybeans was increased and vetch decreased by the asso- 
ciation. There was a reduction in both when kafir and soybeans 
were grown together, but when kafir and vetch were grown together 



66 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

there was an increase in the kafir and a decrease in vetch. In Virginia 
soil oats lost in percentage of nitrogen when grown with soybeans, 
while the beans gained somewhat. In the oat-vetch combination oats 
gained somewhat, while vetch lost considerably. Barley with soy- 
beans lost considerably, while soybeans gained shghtly. Barley when 
grown with vetch remained unchanged, while vetch lost considerably. 
With kafir and soybeans, kafir increased somewhat while soybeans 
lost considerably. Kafir also increased with vetch, while vetch lost. 

In conclusion, legume-nonlegume combinations were grown with 
soybeans and purple vetch as the legumes and oats, barley, and kafir 
as the nonlegumes. The yield of dry matter, yield of total nitrogen, 
and percentage of nitrogen were compared when these crops were 
grown both alone and in association. Parallel experiments were con- 
ducted on three types of soil, semiarid from near Riverside, Cal,., 
Great Plains from near A/lanhattan, Kans., and eastern humid from 
Arlington, Va. On each soil each crop was grown in triplicate in 
large galvanized buckets holding about 45 kg. of soil. Duplicate de- 
terminations for total nitrogen were made on the crop and soil from 
each bucket. The percentage of nitrogen in oats was increased when 
grown with soybeans and vetch in all soils except with soybeans in 
Virginia soil. Barley lost in percentage of nitrogen with soybeans 
in all soils. Barley gained with vetch in California soil, lost in Kansas 
soil, and remained unchanged in Virginia soil. Kafir gained in 
percentage of nitrogen with soybeans and vetch in all soils and with 
the exception of Kansas soil it lost with soybeans. Soybeans with 
oats and barley gained in all soils, while with kafir it gained in Cali- 
fornia and lost in Kansas and Virginia soil. Vetch with oats gained 
in California soil and lost in Kansas and Virginia soil. It lost with 
barley and kafir in all soils. 



PIAYES & STAKMAN I RUST RESISTANCE IN TIMOTHY. 



67 



RUST RESISTANCE IN TIMOTHY.^ 

H. K. Hayes and E. C. Stakman. 

INTRODUCTION. 

Among the first published papers on improvement in timothy is a 
short report by Hays (4)- of variations observed at the Minnesota 
station, together with a discussion of the possibiHties of improving 
this crop. Extensive breeding studies with timothy have been carried 
on at the Cornell University station by Webber (10) and results of 
much promise have been obtained. A number of the improved sorts 
have given increased yield and also a better quality of hay than the 
commercial varieties. Aside from agronomic characters, such as 
stooling, height, and vigor, differences were observed in susceptibilit)* 
to rust (Piiccinia graniinis). These differences in rust resistance 
were believed to be partially responsible for the yielding ability of 
these new sorts. 

EXPERIMENTAL PLAN. 

A project was outlined in 191 6 for timothy selection studies at the 
Minnesota station. For the foundation stock 1 1 of the better Cornell 
sorts were obtained thru the kindness of Dr. C. H. Myers, who 'has 
charge of the timothy improvement work at Ithaca. Six of the better 
Minnesota selections were also grown. Seedlings were started in 
the greenhouse in the spring and approximately 125 plants of each 
selection were placed in the field in rows 4 feet apart, the plants 
being spaced 3 feet apart in the row. 

Correlated data were taken in 191 7 on such important characters 
as yield, erectness, average length of head, height, number of stools, 
and resistance to rust. All of the above data except those on rust 
were taken on the first growth the latter part of June. Spores were 
then collected from an infected timothy field and as soon as the 
second growth of the plants was well started they were sprayed with 
rust spores and data taken some time later on the amount of infection. 
As nearly all plants of the Minnesota selections were heavily rusted 
the epidemic was considered to be a satisfactory one. 

It w^as planned to take individual plant data in 1918 and then save 

1 Published with the approval of the Director as Paper No. 139 of the journal 
series of the Minnesota Agricultural Experiment Station, University Farm, St. 
Paul, Minn. Received for publication, October 22, 1918. 

2 Figures in parentheses refer to " Literature cited," p. 69. 



68 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

seed from a few of the better plants as determined by the correlated 
data for the two crop seasons. These selected plants were to be 
propagated by seed to determine transmission of their characters and 
by bulblets for the purpose of determining reliability of the data 
taken. Due to the severe winter of 191 7, however, practically all of 
the plants were winterkilled. Because of the pressure of other work 
and the difficulty of obtaining field and laboratory assistants it seems 
impossible to repeat the experiment at this time. As some informa- 
tion regarding resistance has been obtained a short note is here 
presented. 

EXPERIMENTAL RESULTS. 

The plants were placed in four groups according to the amount of 
rust present, as follows: Group i, no rust; group 2, slight infection; 
group 3, moderate infection ; and group 4, heavily rusted. 

The following data are given in Table i : Number of plants in the 
different rust classes and average rust class, average yield per plant 
in pounds, average erectness with i as a basis of an erect plant and 
10 a procumbent one, average length of head, average height in centi- 
meters, and stooling. 



Table i. — Rust resistance in timothy in relation to other characters, as shown 

by various data. 



Variety. 


I. 


Riftt c 

^- 


lasses 
3- 


4 


Rust, 
mean. 


Average 
yield per 
plant. 


Erect- 
ness, 
mean. 


Average 
length 
of head. 


Average 
height. 


Average 
number 
of stools^ 














Pounds. 




Cm. 


Cm. 




Cornell 1611 


80 


II 


I 




I.I 


I.O 


2.3 


II.9 


88 


122 




77 


26 


3 


2 


1-3 


I.O 


2.2 


18.3 


88 


138 




79 


15 


9 


2 


1-3 


•9 


3-1 


12.3 


85 


141 


Cornell 1635 


61 


14 


9 


3 


1-5 


.8 


2.9 


II.4 


85 


109 


Cornell 1671 


56 


13 


13 


5 


1.6 


.8 


2.9 


II.6 


89 


123 


Cornell 1676 


87 


10 


3 


6 


1-3 


•9 


2.9 


I3-I 


87 


116 


Cornell 1687 


86 


12 


9 


6 


1.4 


•9 


3-7 


1 1 -3 


88 


131 


Cornell 1715 


90 


II 


6 


3 


1-3 


.8 


3.0 


10.3 


86 


98 


Cornell 1743 


100 


3 


12 


7 


1.4 


I.O 


5.6 


10.9 


84 


134 




36 




4 




1.2 


.9 


5-7 


II-5 


83 


142 




32 


5 


5 




1.4 


.9 


3-1 


12.9 


86 


117 


U. S. Dept. Sel. I 


2 


12 


70 


40 


3-2 


.6 


2.6 


13.0 


91 


64 


U. S. Dept. Sel. 2 


4 


4 


19 


13 


3.0 


.8 


3-3 


10.9 


87 


90 


U. S. Dept. Sel. 3 




7 


15 


9 


3-1 


.8 


2.8 


13-3 


92 


72 


L. L. May Sel. i 


2 


3 


24 


15 


3-2 


.6 


2.3 


12.4 


86 


70 


L. L. May Sel. 2 


8 


5 


25 


6 


2.7 


.6 


3-1 


10. 1 


80 


92 


Griggs Bros. Sel. i. . . 


I 


I 


15 


5 


3-1 


•7 


3-0 


12.8 


86 


91 



The striking fact is that the Cornell selections show a high per- 
centage of resistant plants, while the Minnesota selections are very 
susceptible. The Cornell and Minnesota selections average about the 



HAYES & STAKMAN : RUST RESISTANCE IN TIMOTHY. 



69 



same in height, aUhough the former average somewhat higher in 
yield. Cornell types proved much superior in stooling ability; this 
may explain their higher yield. These results indicate that the pro- 
duction of a rust-resistant timothy could be very easily accomplished. 

Breeding for disease resistance has given very promising results in 
some cases. Notable examples with economic plants as a result of 
hybridization are the work of Orton in producing a wilt-resistant 
watermelon by crossing a resistant citron and a susceptible water- 
melon (i) and Biffen's (2) production of a high-grade wheat re- 
sistant to yellow or stripe rust (Puccinia glumarum). Examples of 
improvement obtained by selection among economic plants are . wilt 
resistance in cotton and other crops (7), wilt resistance in flax (3), 
and the production of a cabbage resistant to the Fusarium or yellows 
disease (5). 

As Orton's wilt-resistant watermelon did not prove resistant on the 
Pacific Coast it seems logical to conclude that breeding for disease 
resistance is often a local problem. Bolley has shown that a variety 
of flax which is resistant may lose this quality if grown for a number 
of years on soil which is free from the disease-producing organism. 

Experiments conducted cooperatively with the Office of Cereal In- 
vestigations, U. S. Dept. of Agriculture, at the Minnesota station (6, 
8, 9) show the growing complexity of some problems in disease resist- 
ance. As an example, wheats which are susceptible in the Northwest 
to the black stem rust are resistant to the rust collected on the Pacific 
Coast or the Southeastern States. Different biologic forms are the 
cause of this variation in susceptibility. Recent studies have shown 
that there are many biologic forms of the wheat stem rust in the 
United States which can only be differentiated by their reaction to 
different host plants. 

Data of this nature show the need of closer cooperation between 
investigators who are attacking the same general problem. Such co- 
operation would, we believe, prove of national significance and could 
be attained without serious less of prestige for each investigator 
concerned. 

Literature Cited. 

1. Babcock, E. B., and Clausen, R. E. Genetics in Relation to Agriculture, 

p. 413-415. McGraw-Hill Book Company, 1918. 

2. BiFFEN, R. A. Systematized plant breeding. In Science and the Nation, 

p. 157. Cambridge, 1917. 

3. BoLLEY, H. L. The importance of maintaining a constant elimination 

factor in association with a constant nutrition factor in plant breeding. 
In 8th Ann. Rpt. Amer. Breeders' Assoc., p. 508-514. 1912. 



70 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



4. Hays, W. M. Improvement of timothy. Minn. Agr. Expt. Sta. Bui. 20, 

p. 45, 46. 1892. 

5. Jones, L. R., and Oilman, J. G. The control of cabbage yellows through 

disease resistance. Wis. Agr. Expt. Sta. Research Bui. 38. 191 5. 

6. Levine, M. N., and Stakman, E. C. A third biologic form of Puccinia 

graminis on wheat. In U. S. Dept. Agr., Jour. Agr. Research, v. 13, no.. 
12, p. 651-654- 1918. 

7. Orton, W. a. Breeding for disease resistance in plants. In Amer. Jour. 

Bot., 5 : 279-283. 1918. 

8. Stakman, E. C, and Hoerner, G. R. The occurrence of Puccinia graminis 

tritici compacti in the southern United States. In Phytopath., v. 8, no. 4, 
p. 141-149. 1918. 

9. Stakman, E. C., and Piemeisel, F. J. Biologic forms of Puccinia graminis 

on cereals and grasses. In U. S. Dept. Agr., Jour. Agr. Research, v. 10, 
no. 9, p. 429-495. 1917. 
10. Webber, Herbert J. The production of new and improved varieties of 
timothy. N. Y. (Cornell Univ.) Agr. Expt. Sta. Bui, 313, p. 339-381. 
1912. 



THE EFFECT OF HEAT ON THE LIME REQUIREMENTS OF 

SOILS.^ 

H. A. NoYEs. 

Brown and Johnson- have found that the reaction of a soil by the 
Veitch method is changed by grinding the soil. Conner^ has found 
that keeping soils at different moisture contents alters their acidities. 
Heat is known to have an effect on the hydrogen ion concentration of 
a soil.* In a previous paper^ the present writer reported a soil giving 
an acid reaction by the Hopkins potassium-nitrate method^ when, 
under field conditions, limestone fragments varying in size from a 
kernel of wheat to 2 cm. in diameter were present. The first step in 

1 Contribution from the Purdue University Agricultural Experiment Sta- 
tion, La Fayette, Ind. Received for publication July 31, 1918. 

2 Brown, P. E., and Johnson, H. W. Effect of grinding the soil on its reac- 
tion as determined by the Veitch method. In Jour. Ind. Eng. Chem., 7 : 776, 
777. 1915. 

3 Conner, S. D. Soil acidity as affected by soil moisture. In U. S. Dept. 
Agr., Jour. Agr. Research. In press. 

* Sharp, L. T., and Hoagland, D. R. Acidity and adsorption in soils as meas- 
ured by the hydrogen electrode. In U. S. Dept. Agr., Jour. Agr. Research, 7: 
123-145. 1916. 

5 Noyes, H. A. Study of a soil containing residual lirhestone. In Jour. 
Assoc. Off. Agr. Chem., 3: I5i-i53- iQi?- 

6 Official methods of analysis. U. S. Dept. Agr., Bur. Chem. Bui. 107, p. 20. 
1908. 



NOYES : LIME REQUIREMENTS OF SOILS. 



71 



the determination of the acidity of the soil by the Veitch method^ is 
to treat it with dilute limewater and evaporate the mixture to dryness 
on the steam bath. The work reported here was done to see if the 
evaporation on the steam bath caused changes that affected the acidity. 

The soil was a residual silty clay loam containing about 60 percent 
of very fine silt and 20 percent of clay and is underlain with limestone 
rock. Samples were taken to represent different depths at different 
places, brought to the laboratory, air dried, crushed with a wooden 
rolHng pin, and sieved. All the material except that of a stony nature 
was worked down to pass a i-mm. sieve and constituted the sample 
analyzed. Those samples from which limestone particles were sieved 
put were tested by (i) the Hopkins potassium nitrate method, (2) the 
Veitch method using no limewater, and (3) the Veitch method using 
no limewater and not evaporating on the steam bath. The results 
are given in Table i. 



Table i. — Acidity of soils containing limestone, as determined by three methods 

of testing. 



Sample No. 


Depth of sample, 
inches. 


Hopkins method, 
lime requirement per 
3,000,000 pounds 
of soil. 


Vietch method, no 

Evaporated on 
steam bath. 


limewater added. 

Not evaporated on 
steam bath. 


X-28 


36 to 41 


Alkaline 


Alkaline 


Alkaline 


XI-28 


18 to 27 


37.5 


do. 


Acid 




27 to 36 


56.4 


do. 


do. 




36 to 45 


150.0 


do. 


do. 


III-51 


9 to 18 


Alkaline 


do. 


Alkaline 




18 to 27 


56.4 


do. 


Acid 




27 to 36 


75-0 


do. 


do. 




36 to 45 


18.9 


do. 


do. 



The Veitch method is quite generally taken as giving the lime re- 
quirement of a soil. The results here reported show that there are 
reactions taking place in the soil at the steam bath temperature that 
do not take place when the soil and water mixture is not heated. 
The Veitch determination gives the reactions between soil, water, and 
calcium hydroxide at steam bath temperature and does not represent 
the lime requirement of the soil at ordinary temperature. 

^ Veitch, F. P. Comparison of methods for the estimation of soil acidity. 
In Amer. Chem. Jour., 26: 62>7-()6i2. 1904. 



72 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



THE OCCURRENCE OF DWARFNESS IN OATS.^ 

C. W. Warburton. 

In the course of studies of selections from certain oat varieties 
grown in head rows on irrigated land at the Aberdeen (Idaho) sub- 
station in 1916, one row of Victory oats was found in which 8 of the 
20 plants were of an entirely distinct type. While 12 of the 20 were 
normal plants of the variety, maturing at the usual time and reaching 
the same height as those in adjoining rows, these 8 plants were simply 
dense tufts of basal leaves with occasional culms not over 9 inches in 
height, bearing very small panicles. At the time these plants were 
found, early August, the normal plants were nearing maturity, while 
the upper portions of the panicles on the dwarf plants were just 
emerging from the sheaths. In most cases only 3 or 4 spikelets 
emerged, tho a few additional ones remained enclosed within the 
sheaths. These dwarf plants for the most part failed to mature seeds 
before frost, tho they w^ere watered and protected from injury. The 
few seeds which were produced were saved, as were also the seeds 
from the tall plants in the same row. A tall and a dwarf plant from 
this row are shown in Plate 2, figure i, while figure 2 shows the entire 
row. 

The few seeds matured by the dwarf plants of the previous year 
were sown in 19 17, and all those which were viable produced dwarf 
plants exactly like the parents. About 40 seeds from each of 10 of 
the 12 tall plants were sown in individual plant rows. Of these 10 
plants, 4 produced all tall plants and 6 produced both tall and dwarf 
plants like those in the original row. In all, 168 tall plants and 66 
dwarfs were produced, a ratio of 2.55 to i. Some of the rows, how- 
ever, showed an exact 3 to i ratio. 

In 1918, a part of the seed produced in 1917 from the individual 
tall plants in four of these segregating rows was sown again at Aber- 
deen. Seed from the dwarfs was also sown, as was some from the 
rows showing all tall plants the previous year. All of the seed pro- 
duced by both tall and dwarf plants in one of the segregating rows 
was sent to Dr. H. H. Love at Cornell University and all from the 
remaining one to Prof. H. K. Hayes at the Minnesota station. 

At Aberdeen, seed from the rows producing all tall plants in 191 7 

1 Contribution from the Bureau of Plant Industry, U. S. Department of 
Agriculture, Washington, D. C. Published by permission of the Secretary of 
Agriculture. Received for publication December 17, 1918. 



Journal of the American Society of Agronomy. Plate 2. 




Fig. I. A dwarf and a tall plant from the original row in which dwarf oats 

were found. 




Fig. 2. The original row of Victory oats in which dwarf plants were found. 
The green tufts are noticeable at various places in the row. 



WARBURTON I DWARF OATS. 



73 



again produced all tall plants in 191 8, and seed from dwarf plants in 
segregating rows produced dwarf plants, showing that dwarf ness in 
this strain is recessive. Of the 117 tall plants produced in 1917 in 4 
segregating rows, 46 produced all tall plants in 1918 and 71 again 
segregated into tall and dwarf, whereas it was to be expected that 39 
would breed true for tallness and 78 would segregate in a ratio of 3 
tall to I dwarf. The total number of plants produced in these 
71 rows was 837, of which 628 were tall and 209 dwarf, an exact 3 to 
I ratio. The detailed figures for each family are shown in Table i,^ 
together with the records from the Cornell and Minnesota stations. 



Table i. — Progeny record of six heterozygous plants produced in igi6 in a 
head row of oats in which a dwarf form appeared.'^ 





Progeny record in 191 7. 


Progeny record in iqi8 of tall plants of the previous year. 


Plant No. 










Progeny recor 


d of hetero- 


Tall. 


Dwarf. 


Homozy- 


Heterozy- 


zygous plants. 








gous. 


gous. 


Tall. 


Dwarf. 


I 


29 


10 


8 


21 


180 


73 


2 


31 


10 


17 


14 


125 


34 ■ 


.3 


30 


9 


9 


21 


185 


59 


4 


27 


14 


12 


15 


138 


43 


5 


24 


14 


10 


14 


326 


95 


6 


27 


9 


9 


18 


582 


210 


Totals 


168 


66 


65 


103 


1.536 


S14 





The progeny of plant 5 was grown at Cornell University in 1918 and that 
of plant 6 at the Minnesota station. 



Doctor Love grew the progeny of 24 plants from a single heter- 
ozygous row of 1917. Of these 24 plants, 10 proved to be homozogous 
for tallness, a proponderance of homozygous plants over the expected 
number of 8 in 24. The 14 heterozygous plants produced 326 tall 
and 95 dwarf plants, a ratio of 3.43 to i, showing a preponderance of 
tall plants. Doctor Love suggests that this " may be due to the fact 
that the dwarfs are not so hardy and some of them may die out in the 
very early stages." None of the seeds from dwarf plants of the 
1917 crop proved viable, and none of the dwarfs produced from 
heterozygous tall plants matured seed in 1918 in the open, but some 
are now^ being grown in the greenhouse in the hope of producing viable 
seed there. 

Of the family growm at the INTinnesota station. Professor Hayes 
reports that the seed from dwarf plants again produced dwarfs. Of 

2 The writer is indebted to Mr. T. R. Stanton for the data recorded at Aber- 
deen in 1918. 



74 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



the 27 tall plants of the 1917 crop, 18 proved to be heterozygous, the 
exact proportion to be expected if dwarfness is a simple recessive 
character. The 18 heterozygous tall plants produced 582 tall and 
210 dwarf plants in 1918, a ratio of 2.77 tall to i dwarf. 

Summarizing the results obtained at Aberdeen, Ithaca, and St. 
Paul, 65 tall plants out of 168 produced in 191 7 from 6 families 
proved to be homozygous for tallness and 103 proved to be hetero- 
zygous, a proponderance of homozygous plants, as the expected num- 
bers are 56 and 112. The 103 homozygous plants produced 1,536 tall 
and 514 dwarf plants, almost an exact ratio of 3 tall to i dwarf. 

No adequate explanation of the sudden appearance of this dwarf 
form has yet been found. The plant from which it developed grew 
in 191 5 in the varietal classification nursery at Aberdeen, and for two 
or three years previous this lot of Victory oats had been grown from 
bulk seed produced from rows in this nursery. The Victory oat 
originated as a pure-line selection from a commercial variety, not a 
hybrid, at the Swedish Seed-Breeding Institute, Svalof, Sweden. The 
tall plants produced in the original row with the dwarfs in 1916 and 
those from both homozygous and heterozygous individuals in 191 7 and 
19 1 8 are in every visible respect normal Victory oats, and there is no 
evidence that hybridization has entered into the production of this 
dwarf, tho natural hybrids in oats are not infrequent at Aberdeen. 

The writer has not found any record in literature of the occurrence 
of similar dwarfs in oats nor of exactly parallel cases in other cereals. 
Early in 1916, however, his attention was called by Prof. G. H. Cutler 
to the occurrence of dwarf forms in selections of Marquis wheat. 
This variety is a selection from a hybrid between Red Fife and a 
dwarf Indian wheat, tho the Indian parent is much less dwarf than 
the forms found by Cutler and described elsewhere in this issue of 
the Journal of the American Society of Agronomy.^ 

Altho dwarf wheats appear to be not uncommon in hybrids pro- 
duced in Australia, their occurrence in America has not been noted, 
so far as known, except by Cutler. Richardson* reports that of 
15,800 plants of hybrid parentage grown at Longerenong in 1912, 28 
dwarf or grass-tuft plants appeared, tho there were none among 
35,000 plants in straight selection plots. At Rutherglen 45 grass- 
tuft plants were found in 18,500 cross-bred plants, but none in the 
regular selections from varieties. The dwarf plants appeared in 12 

sCutler, G. H. A dwarf wheat. In Jour. Amer. Soc. Agron.,.ii : 76^78. 1919. 
4 Richardson, A. E. V. Wheat and its cultivation. Victoria Dept. Agr. Bui. 
22, p. 115, 116. 1913. 



WARBURTON I DWARF OATS. 



75 



different crosses, of which 6 were crosses with Indian wheats. The 
average height of the plants was 9 inches. Less than 50 percent 
formed heads, and only 9 percent produced grain. 

The most striking and complete records of dwarf wheat plants, 
however, are those of Farrer.^ Tho the reading of Farrer's paper in 
its entirety is recommended to those who are interested in cereal 
breeding, it seems well worth while to quote at length from it here, 
as it may not be available in many libraries. Farrer writes : 

For the purpose of getting abundant material to select from, I like to make 
my crosses between varieties which differ sufficiently in type for their progeny 
to be highly variable. Now, it is quite common to find amongst the progeny of 
such crosses, especially in the second and future generations until they have 
been selected out, plants which are entirely different from ordinary wheat 
plants. These plants, which can be recognized long before the wheat plants 
come into ear, have the appearance of compact and generally dense clumps of 
grass with leaves which are stiffer, narrower, and much more erect than those 
of ordinary wheat plants. They remind me, in fact, of the young plants of 
the spelt, Triticum monococcum, which I grew one year. Sometimes, but very 
far from always, and later than the wheat plants in their respective rows, they 
produce a few — generally only one or two — meagre heads on stalks which 
scarcely rise out of the clumps of leaves, but many of them usually die off 
before they are old enough to head. I have never noticed that the heads they 
bear partake in their appearance of those of the wheat plants from which they 
have come ; indeed, it usually happens that they are much less compact and 
thinner, as well as smaller than the ears of any variety of wheat. Occasionally, 
indeed pretty frequently, one of them will be met with which looks as if it was 
struggling to rise to the dignity of a wheat plant, and its leaves will then lose 
their characteristic stiffness and narrowness, and it will even succeed in bearing 
two or three fairly good heads on stalks which have risen a few inches above 
the clump of leaves. In 1895, I harvested a few ears from grass-clump plants 
and planted the seeds from them. In one case the plants they produced (about 
thirty in number) were all grass-clump plant's; but in others they were mix- 
tures of grass-clump plants and wheat plants — sometimes the one predominating 
and sometimes the other. It is usually the second generation of the cross-bred 
before grass-clump plants appear; after which they continue to show them- 
selves in diminishing numbers for a season or two, when they disappear — are 
selected out; but they are occasionally produced in the first generation, as is 
the case the present season with the plants of a cross between the " Bokhara 
Desert" wheat and a Fife-Indian variety, all of which (four in number) that 
grew from the seeds I made in crossing, are grass-clump plants. It is seldom 
that these grass-clump plants result from crosses between varieties which are 
in general cultivation in Europe and America. . . . 

There is one suggestive fact in connection with the occurrence of these grass- 
clump plants. It is that in general there is a poorer stand than is usual in the 
drills that contain them, and the poorest in those that have the greatest number 

5 Farrer, William. The making and improvement of Australian wheat. In 
Agr. Gaz. N. S. Wales, 9: 152-156. 1898. 



76 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

of them. It looks as if the crosses which produce such plants are violent 
enough for the seeds, which produce them, to be of low germinating power. . . . 

Grass-clumps plants are produced in the greatest number by first crosses 
between different types of bread wheat, and appear to be produced by crosses 
between bread wheats alone ; at any rate, the crosses I have made between 
bread wheat and macaroni wheats, between bread wheat and poulard wheats, 
and between bread wheats and Triticum amyleum have produced none. 

While neither the dwarf wheat nor the dwarf oat plants are likely 
to prove of economic value, they are interesting variations well worth 
further study. It is the intention, as opportunity offers, to use the 
dwarf oat plants in inheritance studies with hybrids and also to search 
carefully for other dwarf forms. If other workers wish to study 
this dwarf oat, the writer will be glad to furnish a few seeds on 
request. 

A DWARF WHEATi 

G. H. Cutler. 

When the writer was professor of cereal husbandry at the Univer- 
sity of Saskatchewan, where it was his privilege to plan and inau- 
gurate the cereal crop improvement experiments, an interesting dis- 
covery was made. In a plot of commercial Marquis wheat, which 
had not been specially selected since it was originated and multiplied 
for distribution, a plant of very low stature appeared — a dwarf 
wheat. It measured about 9 inches in height, while others of similar 
origin measured as high as 40 inches. 

During the harvest season of 191 3 the writer selected typical Mar- 
quis heads from plants that in every way appeared normal. In the 
winter of 1913-14, after reserving sufficient material to sow a foun- 
dation plot of one-fiftieth acre, some 200 heads were chosen from the 
balance to form the basis for special studies in heredity. In making 
the latter selection special care was exercised to take only typical 
heads. Each head was then thrashed and the product placed in an 
envelope. A head row of each consisting of 20 seeds was then sown. 

Before harvest it was quite evident that some head rows possessed 
more variation than was usual. The widest departure from the Mar- 
quis type was revealed by head row No. 186, this row including plants 
ranging from 9 to 40 inches high. Other variable characters present 
were color of chaff, beardedness, shape of kernel, etc., but these 
variations were not confined to row No. 186. 

1 Contribution from the University of Alberta, Edmonton (South), Alfa. 
Received for publication January 18, 1919. 



CUTLER. A DWARF WHEAT. 



77 



In 191 5 a head row from each plant was sown. The results at 
harvest showed that the plants of lowest stature gave rise to a large 
percentage of low stature plants, in some cases 100 percent, whereas 
the normal tails produced 100 percent tails and a careful analysis of 
the intermediates revealed 25 percent dwarfs, thus behaving as a 
simple ]\Iendelian character. It should also be pointed out that the 
other variable characters revealed a significant segregation, altho 
more difficult to differentiate. Beardedness was distinctly Mendelian. 
The work was again conducted in 1916, when the results again pre- 
ponderately bore out the fact that the dwarf condition was hereditary. 
In the winter of 191 7 the writer severed his official relations with the 
University of Saskatchewan to take up a somewhat broader field of 
work in the University of Alberta and was therefore forced to give 
up these studies. 

Some interesting queries arise regarding this peculiar form: 

1. What is the origin of this dwarf? The fact that this form oc- 
curs regularly in each generation and is not found in other varieties 
of wheat growing on similar soil conditions indicates that the cause 
is not to be looked for in the environment. It cannot be due to lack 
of nutrition. 

2. If hereditary, why should Marquis wheat give rise to it? Rich- 
ardson^ states that these forms appeared in twelve different crosses, 
of which six were crosses with Indian wheats. The average height 
of the " tufts " was 9 inches. Farrer^ observed a number of these 
clumps in his cross bred plots from time to time. He does not state 
that his low stature forms resulted from Indian wheat crosses, altho 
it is worthy of note that he made extensive use of such wheats 
in his breeding work. He does state, however, that these grass- 
clump plants were produced in the greatest numbers by first crosses 
between widely different types of bread wheat (T. sativitm) and ap- 
pear to be produced by crosses between bread wheats alone. 

Marquis wheat is a descendant from an Indian wheat known as 
Hard Red Calcutta, the other parent being Red Fife, a widely dif- 
ferent type of wheat. As this form was discovered frequently in 
Marquis in 1914, 1915, and 1916, and as dwarfs were found in other 
varieties of wheat similarly treated, including Red Fife, is it fair to 
conclude that the origin of this dwarf wheat can be traced to its 
pecuHar Indian ancestor? 

2 Richardson, A. E. V. Wheat and its cultivation. Victoria Dept. Agr. Bui. 
22, p. 115, 116. 1913. 

3 Farrer, William. The making and improvement of Australian wheat. In 
Agr. Gaz. N. S. Wales, 9: 152-156. 1898. 



78 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



3. Is it the result of natural crossing between two different strains 
of Marquis having a tendency towards dwarfness ? Natural crossing 
has been shown to be not at all unusual among wheats on the ex- 
perimental plots at Saskatoon; therefore such a process might easily 
come within the range of probability. No crosses were made to con- 
firm this or query No. 2. 

4. All observations seemed to point to the fact that this dwarf con- 
dition was a simple dominant to tallness, despite the fact that the 
original parent was to all intents and purposes a normal tall. Since 
the original selection was merely a head selection from vigorous 
plants one cannot be quite certain as to its absolute height, altho the 
writer feels confident that its height was not noticeably unusual. It 
is conceivable, however, that it was heterozygous in this particular. 

AGRONOMIC AFFAIRS. 
MEMBERSHIP CHANGES. 

The address list as printed in the December issue contained 509 
names. Since that time 7 new members have been added, i has 
been reinstated, and 2 have resigned, making a net gain of 6 and a 
present membership of 515. The names and addresses of the new 
members, with such changes of address as have been brought to the 
attention of the secretary or the editor, are as follows: 

New Members. 

Fahrnkopf, H. F. T., 216 Agrl. Bldg., Univ. of 111., Urbana, 111. 
Fuller, F. E., Montana State College, Bozeman, Mont. 
Hastings, H. G., H. G. Hastings Co., Atlanta, Ga. 
Oldenburg, F. W., College Park, Md. 

Smith, Oliver, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Steinmetz, F. H., 2362 Bourne Ave., St. Paul, Minn. 
Stoudt, John M., Hershey, Pa. 

Member Reinstated. 
Carroll, J. S. 

Members Resigned. 
Carroll, J. S. Foord, J. A. 

Changes of Address. 

Delw^iche, E. J., R. F. D. No. 3, Green Bay, Wis. 
Emerson, Paul, University of Idaho, Moscow, Idaho. 



NOTES AND NEWS. 



79 



GiLUS, M. C, Agr. Expt. Sta., La Fayette, Ind. 
Hopkins, E. S., Olds, Alberta, Canada. 
Kraft, J. S., Bryan, Texas. 

Martin, John H., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Newton, Robert, Senneville, Quebec, Canada. 

Pridmore, J. C, 613 Continental Bank & Trust Bldg., Shreveport, La. 
Walter, E. J., 21 Fifteenth Ave., Columbus, Ohio. 

NOTES AND NEWS. 

Ross R. Childs, who has been in the aviation section of the military 
service for the past several months, has now received his discharge 
and is again with the office of cereal investigations, U. S. Department 
of Agriculture. At present he is engaged in field work in the 
Southeastern States, in connection with the extension of rice pro- 
duction. 

A. D. Ellison, until recently a lieutenant in the gas defense service, 
has received his discharge and is now engaged in extension work 
for the U. S. Department of Agriculture in connection with the in- 
creased production of flax in the Southwestern States. 

Paul Emerson, for the past year soil bacteriologist of the Maryland 
station, is now associate biologist at the Idaho station. 

S. C. Harmon, instructor in agronomy and associate agronomist 
of the Virginia station, has resigned to take charge of agricultural 
work in the high school at Driver, Va. He has been succeeded by 
F. S. Glassert. 

E. R. Lloyd, director of the experiment station and extension 
service in Mississippi for many years, has resigned to assume the 
directorship of the Memphis Farm Development Bureau. He has 
been connected with the Mississippi college and station since 1888. 
R. S. Wilson, formerly assistant director of extension, succeeds him 
as director of extension, while J. R. Ricks, formerly vice-director 
of the experiment station, now becomes station director. 

David Lubin, founder of the International Institute of Agriculture 
at Rome and American member of the board of directors of the 
institute since its formation, died in Rome January 9 from influenza, 
at the age of about 78 years. He was formerly a merchant in Sacra- 
mento, Cal., but has been intensely interested in agriculture for many 
years. 

John H. Martin, superintendent of the Harney Branch Field Sta- 
tion, Burns, Oregon, for the past year, has resigned to become as- 



80 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

sistant in wheat investigations with the Federal office of cereal 
investigations. 

Raymond A. Pearson, assistant secretary of agriculture since 
August, 1 91 7, resigned in October to resume his duties as president 
of Iowa State College. He was succeeded by George I. Christie, 
director of extension in Indiana and for several months previous as- 
sistant to the secretary of agriculture. Mr. Christie retains his con- 
nection with the Indiana extension service. 

A. J. Pieters and W. A. Wheeler, of the Department of Agricul- 
ture, sailed for Europe December 30 to gather information on clover, 
grass, and vegetable seed stocks and requirements of European 
countries. 

J. E. Readhimer, county agriculturist of Kane Co., 111., since 1913, 
is now departmental adviser in soils in the University of Illinois. 

H. S. Records has been appointed assistant professor of agronomy 
and agronomist at the Northwest Experiment Farm, Crookston, Minn. 

G. L. Schuster, formerly assistant in field crops at Ohio State 
University, is now vocational agriculturist in the Lancaster (Ohio) 
high school. 

Harry Umberger, county agent leader in Kansas for the past 
several years, is acting director of extension in that State, succeeding 
E. C. Johnson, resigned to become director of the experiment station 
and dean of the college of argiculture at Pullman, Wash. 

Carl Vrooman, assistant secretary of agriculture since 1914, has 
resigned because of ill health. 

R. C. Wright, formerly engaged in soil fertility investigations in 
the Bureau of Plant Industry, has been transferred to refrigeration 
studies in the Bureau of Markets, U. S. Department of Agriculture. 

A recent publication of interest to agronomists is Botanical Ab- 
stracts, the first number of which made its appearance in September. 
Burton E. Livingston of Johns Hopkins University is editor-in-chief, 
assisted by an able board of editors on special subjects. The purpose 
of the publication is stated to be " to supply prompt citations and 
abstracts of all papers dealing with botanical subjects, wherever 
published, just as soon as possible after they appear." This journal, 
which is published by Williams & Wilkins Company, Baltimore, will 
be issued monthly, making semi-annual volumes of about 300 pages 
each. The subscription price is $6.00. The first number contains 
abstracts or citations of 206 papers. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. March, 1919. No. 3 



FIELD TECHNIC IN DETERMINING YIELDS OF EXPERI- 
MENTAL PLOTS BY THE SQUARE YARD 
METHOD.! 

A. C. Arny and F. H. Steinmetz. 

INTRODUCTION. 

In an article (i)^ giving results of determination of yields by 
harvesting parts of plots as compared with harvesting the entire areas, 
the uses of such a method are outlined and the known literature on 
the subject reviewed. 

Two considerations led to the undertaking of more extensive work 
along this line in 191 8. It seemed desirable (a) to extend the work 
over a period of at least two years and (b) to secure data on a method 
which may be used equally well in sampling broadcasted and drilled 
forages and grains. 

After the compilation of the 1918 results for publication, an article 
by Kiesselbach (4) was called to our attention. Results are given for 
the determination of yields by harvesting 14 entire thirtieth-acre plots 
of seven different varieties or strains of winter wheat as compared 
with the yields secured by the removal of 20 areas 32 by 32 inches 
from each plot at locations 10 feet from the ends at intervals of 14 
feet on alternate sides. The statement is made that, due to the 
severe winterkilling, the 14 plots varied markedly in stand and yield, 
and that, therefore, there was a greater variation between the areas 
removed within any single plot than would normally be expected. 

^ Published with the approval of the Director as paper No. 159 in the Journal 
series of the Minnesota Agricultural Experiment Station, University Farm, St. 
Paul, Minn. Received for publication January 28, 1919. 

2 Figures in parentheses refer to " Literature cited," p. 106. 

81 



82 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



The conclusion reached is that the yield from 20 systematically dis- 
tributed areas 32 by 32 inches may be safely substituted for the yield 
from the plot from which they are taken. 

Materials and Methods, 

The Division of Soils has in operation at the substations at Waseca, 
Morris, Crookston, Grand Rapids, and Duluth, and at the central 




Fig. 7. Outline map of Minnesota showing the location of the experimental 
tracts. (Courtesy of the Division of Soils.) 



station at University Farm, St. Paul, a fertilizer experiment carried 
out on a uniform plan. The location of the substations and the 
central station are indicated in figure 7. 



ARNV & STEINMETZ I DETERMINING PLOT YIELDS. 



83 



Each series on which the experiment is carried out consists of i8 
plots 2 rods by 8 rods or one-tenth acre. The plots are separated by 
2-foot alleys and the series by roadways either cultivated or seeded 
to grass. In addition to the check there are five treatments which 
are designated here as A, B, C, D, and E. The check and each of 
the five treatments occupy in a series three systematically distributed 
plots. On each series lime has been applied crosswise to half of each 
plot. In 19 18 there was available for this work 162 tenth-acre plots, 
located in the State as follows : 18 sown to barley at Waseca; 54 sown 
to wheat at Morris ; 18 sown to oats at Grand Rapids and at Duluth ; 
and 54, of which 18 were sown to winter rye and 36 to wheat, at 
University Farm, St. Paul. 

Ten square yards of the standing grain as indicated in figure 8 
were removed from each plot shortly before harvesting the product 
of the entire plot with the binder. All of the grain was well ripened 
before the square-yard samples were removed. Five square yards 
were located on each half of each plot, i, 2, 3, 9 and 10 on the un- 
Hmed and 4, 5, 6, 7, and 8 on the Hmed half. The square yards were 







a 


dsn 




a 




[D 



Fig. 8., Outline of tenth-acre plots showing location of square yards removed 

in determining yields. 



located not less than 7 feet within the plot from the sides and ends, 
thus avoiding places where the drill lapped in seeding and small in- 
equalities in stand which would not affect materially the yield of the 
entire plot. 

The instrument for laying off the square yards shown at A was 
made of steel 0.75 inch wide and 1.4 inches thick, shaped properly 
and reinforced at the corners. The fourth side shown at B (fig. 9) 
was made of oak. No particular difficulty was experienced in obtain- 



84 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



ing the desired square yards accurately with this instrument. How- 
ever, in all probability, a better instrument can be devised than the 
one used. 

As the square yard's of grain were removed each one was tagged. 
They were then carried out and the heads or panicles with approxi- 
mately one-third of the straw from each 
square yard cut of¥ with a cornknife hav- 
ing a serrated blade and placed separately 
in flour bags. At the substations the flour 
bags containing the unthrashed grain were 
put into large jute bags and shipped to 
University Farm. The bags containing the 
unthrashed grain were hung under the 
broad cornices of a 'building to dry. After 
being dried thoroly, the grain was beaten 
out by hand and the straw and chafif sepa- 
rated by passing through a fanning mill. 
The grain from the square yards may have 
been somewhat lower or higher in moisture content at the time it 
was weighed than the product of the entire plot when it was weighed. 
This would tend to lower or raise the yields from the square yards 
slightly as compared with the yields from the entire plots. The 
weight of the grain removed from each plot in the lO square yards 
was added to that harvested by the binder to determine the yield of 
the entire plot. 




Fig. 9. Instrument used in 
laying off the square yard. 



Method of Determining Yield from the Square Yards. 

The yield of the grain in grams was determined for each square 
yard in order that the various combinations could be made for the 
comparison with the yield secured by harvesting the entire tenth-acre 
plot. In actual practice all the yards removed from any one plot 
would be combined at harvest and only one determination of yield 
made for each plot. 

The combinations of the square yards for the comparison with the 
yields ascertained by the harvesting of the entire tenth-acre plots 
were made as follows. For the determination by 10 square yards the 
yields of the 10 were added and th6 bushels per acre were calculated. 
For the determination by 9 square yards, the yields of square yards 
I to 9 inclusive were totaled and the bushels per acre calculated ; for 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 



85 



8 square yards, 2, 3, 4, 5, 7, 8, 9, and 10; and for 5 square yards, 
numbers 2, 3, 4, 8, and 9 were used. For the determinations by 4 
square yards at the ends and 4 square yards at the center respectively, 
the yields of 2, 5, 7, and 10 and 3, 4, 8, and 9 were totaled and the 
yield in bushels per acre calculated. 

Method of Deriving Probable Error. 

The method of arriving at the probable error for a single determina- 
tion for the yields from the tenth-acre plots and for the square yards 
is that employed by Wood and Stratton (7). This method of work- 
ing probable errors is illustrated and used in presenting the data 
obtained in 1917 (i). For the convenience of the reader the explana- 
tion of the method is repeated. It is briefly as follows : The yields 
of each consecutive pair of plots receiving the same treatment are 
averaged and the deviation from the mean of each pair ascertained. 
Each deviation is then calculated to a percentage of the mean yield of 
the pair. After the deviation in percentage of the mean yield of each 
pair is ascertained, the arithmetical mean of the total number of 
percentage deviations is calculated. This gives the probable error in 
percentage of the mean for a single determination. In deriving the 
probable error in percentage of the mean squared, the deviation in 
percentage of the mean of each pair is squared, the arithmetical mean 
taken, and the square root of the result extracted. 

The procedure in deriving the probable error by the pairing method 
is illustrated by using the yields of the three check tenth-acre plots on 
Series II at the Morris substation, as is shown in Table i. 



Table i. — Example showing method of deriving probable error by the pairing 

method. 



Plot 
No. 


Yield in 
bushels 
per acre. 


Average yield in 
bushels per acre of 
pairs of similarly 
treated plots. 


Deviation in 
bushels per acre 
from the mean 
yields of the pairs. 


Deviation in 
percentage of the 
means of each pair. 


Deviation in 
percentage of the 
means of each 
pair squared. 


I 


18.2 


} 18.0 


0.2 


I.I 


1.2 


7 


17.7 


} '6-7 








13 


15.7 


1.0 




34.8 



The probable errors for single determinations derived from the 
106 pairs of tenth-acre plots and from the 1,073 pairs of square-yard 
areas are given in Table 2. 



86 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Comparison of the Probable Error for Single Determinations of the Yields 
FROM Tenth-Acre Plots and from Square Yard Areas Removed 
FROM Them. 

As is indicated in Table 2, the probable errors in percentage of the 
mean yields for single determinations ascertained by harvesting entire 
tenth-acre plots and square-yard areas from those plots varied con- 
siderably according to location. 

Table 2. — Mean probable error for yields from the tenth-acre plots and from 
the square yards removed from tenth-acre plots ascertained by the pairing 
method (a) in the percentage of the mean yield of each pair and 
(b) in the percentage of mean yield of each pair squared. 

TENTH -ACRE PLOTS. 



Source. 


Location. 


Number 
of plots. 


Number 
of pairs. 


Probable 
error in per- 
centage of 
mean. 


Probable 
error in per- 
centage of 
the mean 
squared. 


Wheat 

Wheat 

Barley 

Rye 

Oats 

All tenth-acres ex- 
cept oats at Grand 
Rapids substation 

Oats 

All tenth-acre plots 


Morris substation 

University Farm 

Waseca substation 

University Farm 

Duluth substation 

Grand Rapids substation. . 


54 
36 
17 
18 

17 

142 
18 
160 


36 
24 
II 
12 
II 

94 
12 
106 


3.85 
4.70 

5-50 
3.10 
4.70 

4.27 

9.13 
4.82 


4.86 

5-45 
6.93 

4- 35 
6.54 

5- 45 
II. 14 

6.35 



SQUARE YARDS REMOVED FROM PLOT. 



Wheat 

Wheat 

Barley 

Wheat and barley . 

Rye 

Oats 

Rye and oats 

Oats 

All square yards . . 



Morris substation . 
University Farm . . 
Waseca substation 

University Farm . . 
Duluth substation. 



Grand Rapids substation. 



540 


358 


8.52 


11.00 


359 


236 


8.36 


10.72 


180 


120 


8.29 


10.52 


1,079 


714 


8.56 


10.82 


180 


120 


.11.51 


15.59 


179 


119 


13.09 


16.01 


359 


239 


12.29 


15.80 


180 


120 


27.50- 


33-00 


1,618 


1,073 


11.52 


1375 



For the yields from the tenth-acre plots the probable error in per- 
centage of the mean for single determinations varied from 3.10 for 
the rye at University Farm to 9.13 for the oats at Grand Rapids; 
and, when the results from all of the tenth-acre plots are considered, 
the probable error in percentage of the mean yields for single de- 
terminations is 4.82. 

The probable error in percentage of the mean yield for single de- 
terminations on the square-yard areas vary from 8.29 for the barley 
at Waseca to 33.00 for the oats at Grand Rapids. When the yields 
of all of the square yard areas are considered, the probable error is 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 



87 



11.52. The oats on a strip running diagonally across several of the 
plots at Grand Rapids were very much shorter than those in other 
portions of the plots. This accounts largely for the wide variation 
in the yields of the square yards at that location. 

The probable error in percentage of the mean for single determina- 
tions, 4.82, where the entire tenth-acre plots were harvested, is very- 
similar to the 5 percent given by Wood and Stratton (7) for plots 
one-eightieth acre in size or larger and the 5.35 percent reported by 
Arny and Garber for tenth-acre plots (i). For the square yards, 
which are Y^sw acre in size, the probable error in percentage of the 
mean, 11.52, when the total number is considered, is practically iden- 
tical with the 12 percent given by Wood and Stratton (7) for areas 
of this size and somewhat greater than the 9.98 percent reported by 
Arny and Garber (i) for plots %280 acre in size. 

Comparison of the probable errors in percentage of the mean and 
probable errors in percentage of the mean squared as given in columns 
5 and 6 of Table 2 show the latter to be the greater in each instance. 
As the probable errors in percentage of the means squared are the 
greater, they are used as the more conservative basis on which to base 
the discussion of the results. 

Table 3. — Probable error in percentage of the mean squared for a single deter- 
mination, for three determinations of yield from tenth-acre plots and 
from one square yard removed from tenth-acre plots, and 
for 10, g, 8, 5, and 4 square yards removed from 
three tenth-acre plots of similar treatment. 

RESULTS FOR IQiS. 



Source. 


Num- 
ber of 


For 

single 
determi- 


For 3 deter- 
minations 
on plots of 


For given number of determina- 
tions by removal of square yards 
from 3 plots of similar treatment. 




pairs. 


nations. 


similar 
treatment. 


10. 


9- 


8. 




4- 


Tenth-acre plots: 

For all crops at all locations. 

For oats at Grand Rapids . . 
Square-yard areas: 

For all crops at all locations. 

For rye at St. Paul and oats 
at Duluth 


106 
12 

1,073 

240 
120 


6.35 
II. 14 

13.75 

15.80 
33.00 


3.67 
6.44 

7.95 

9.13 
19.07 


2.52 

2.89 
6.03 


2.65 

3-04 
6.36 


2.81 

3-23 
6.74 


3-55 

4.08 
8.52 


3- 98 

4- 57 
9-54 


For oats at Grand Rapids . . 




RESULTS FOR 


I917. 












Tenth-acre plots: 

F'or all crops at all locations. 
For oats at Duluth 


168 
12 


7.12 
14-74 

12.93 
16.83 


4.12 
8.51 

7-47 
9.72 












Square-yard areas: 

For all crops at all locations. 
For oats at Duluth 


108 




2.49 

3-24 




3-34 
4.35 


3.79 
4.86 



88 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



In Table 3 are summarized the probable errors in percentage of the 
mean squared for the tenth-acre plots and for the square yards in 
1918, and for convenience the probable errors determined in 1917 are 
also given. 

Examining first the probable errors for single determinations as 
given in column 3 of Table 3, it is seen that in 1918 the error for single 
determinations on tenth-acre plots, is half that on square-yard areas 
when all the plots are considered. The number of determinations in 
each case is sufficiently large to give reliable results. For single deter- 
minations on tenth-acre plots at Grand Rapids, the probable error is 
II. 14 percent, which approximates the 13.75 percent for the square- 
yard areas at all locations. The probable error for single determina- 
tions on square-yard areas at Grand Rapids is 33 percent, which is 
more than twice as great as the probable error for yields on square- 
yard areas at all locations. 

In 191 7 the probable error for single determinations of yield on 
tenth-acre plots, considering all locations, was 7.12 percent. For 
yields on square-yard areas the probable error for single determina- 
tions was 12.93 percent, or nearly twice as great as that for single 
determinations on tenth-acre plots. At Duluth single determinations 
on tenth-acre plots gave a probable error somewhat greater than that 
for square-yard areas, all locations considered. For the determina- 
tion of probable error for the tenth-acre plots at Grand Rapids in 
1918 and at Duluth in 1917 the numbers are scarcely large enough to 
be certain that the results are reliable. 

Having noted that the probable error for single determinations of 
yield on tenth-acre plots was in 1917 and 1918 approximately half 
that for single determinations on square-yard areas, it is obvious that 
equal increases in the number of the determinations on these two sizes 
of plots will reduce the error in approximately the same ratio; Know- 
ing the probable error for single determinations for -yield on tenth- 
acre and square-yard plots, the probable error for any given number 
of determinations for the same treatment may be derived by using the 
formula 

probable error for single determination ^ . . . , , 

— . Exammation of the prob- 

Vnumber of determinations 

able errors for three determinations of yield on tenth-acre plots and 

on square-yard areas as given in the fourth column of Table 3 shows 

that they bear the same relation as in column 3, where the probable 

error is for one determination. 

It has been noted that the probable errors for single determinations 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 



89 



of yield on tenth-acre plots in 1918 and 1917 are approximately half 
those for single determinations on systematically distributed square- 
yard areas. Using the formula given above in deriving the probable 
error for any given number of determinations, it is evident that the 
use of four systematically distributed square-yard areas should re- 
duce the probable error for square-yard areas to approximately that 
for single determinations on tenth-acre plots. Comparison of the 
probable error considering all the locations for three determinations 
of yield on tenth-acre plots with that for 4 square-yard areas removed 
from the same tenth-acre plots as given in columns 4 and 9 of Table 
3 indicates that this is approximately the case in both 1918 and 1917. 
Likewise, 5 square yards removed from 3 tenth-acre plots of like 
treatment gave probable errors approximately equal to or somewhat 
less than those for the 3 tenth-acre plots. Considering the results 
from all tenth-acre plots and all square yards, 8 and 9 square-yard 
areas in 1918 and 9 in 1917 systematically removed from 3 tenth- 
acre plots gave probable errors considerably lower than that for 3 
determinations on tenth-acre plots, and 10 square yards in 1918 gave 
a probable error approximately two-thirds that of the 3 tenth-acre 
plots from which they were removed. 

For the rye at St. Paul and the oats at Duluth in 1918 and for the 
oats at Duluth in 1917 from 5 to 8 systematically distributed square- 
yard areas appear necessary to reduce the probable error to approxi- 
mately that of single determinations on tenth-acre plots. 

At Grand Rapids in 1918 yield determinations from 9 systematically 
distributed square-yard areas removed from 3 tenth-acre plots were 
necessary to reduce the probable error to approximately that for 3 
tenth-acre plots. 

It is important to note in this connection that systematic distribu- 
tion of the small areas is necessary tp secure the desired reduction in 
the probable error from single determinations ; also, that the probable 
error for any number of determinations is based on the probable error 
for single determinations. If the probable error for a single determi- 
nation in any test is low, then the probable error for any number of 
determinations will be relatively low also. 

From the results for the two years the following conclusions may 
be drawn : 

From relatively uniform standing grain 4 to 5 systematically dis- 
tributed square-yard areas removed from tenth-acre plots gave ap- 
proximately the same probable error for yield as harvesting the 
products of entire plots ; and the probable error for the yield from 10 



90 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



square-yard areas removed from tenth-acre plots was approximately 
two-thirds that for the tenth-acre plots from which the square yards 
were removed. 

Where the stands of grain were relatively nonuniform 5 to 10 sys- 
tematically distributed square-yard areas were necessary to reduce 
the probable errors to approximately equal those for the yields from 
the tenth-acre plots from which the square-yard areas were removed. 

These results are strictly applicable for the seasons of 1918 and 
1917 to the plots on the series mentioned. It appears, however, that 
where determinations are sufficiently large, in number and are made 
covering varying conditions of soil and climate probable errors for 
areas of given size are very similar. 

Comparison of Increases in Yield from Different Treatments as Ascer- 
tained BY THE Tenth-Acre Plot and the Square-Yard Methods. 

The probable errors for determinations of yield are of prime impor- 
tance in differentiating between fluctuations due to soil heterogeneity 
and other disturbing factors and the results due to the variable in the 
experiment. 

The odds are 30: i against a difference 3.81 times its probable error 
in one direction only being due to normal variation (7). 

Multiplying the probable errors for three determinations on tenth- 
acre plots and for 10, 9, 8, 5, and 4 determinations on square-yard 
areas removed from 3 tenth-acre plots by 3.81 gives the probable least 
significant diff'erence in yield expressed in percent between any two 
treatments. These differences are given in Table 4. 



Table 4. — Increase in yield expressed in percentages due to fertiliser treatment 
which may be considered significant. 





Three tenth- 


Square yards removed from each three plots 


Source 


acre plots 




of same treatment. 




of same 














treatment. 


10. 


9- 


8. 


5- 


4. 




Percent. 


Per- 


Per- 


Per- 


Per- 


Per- 






cent. 


cent. 


cent. 


cent. 


cent. 


Tenth-acre plots: 














All tenth-acre plots 


13.98 












Plots at Grand Rapids 


24-54 












Square-yard areas: 












All square yards 




9.60 


10.09 


10.70 


13.05 


15.16 


Rye at University Farm and oats 














at Duluth 




II.OI 


11.58 


12.31 


15.54 


17.04 


Oats at Grand Rapids 




22.97 


24.23 


25.68 


32.46 


36.35 



For the tenth-acre plots at all locations except Grand Rapids and 
for 4 square yards at all locations the least differences in yield ex- 



ARNV & STEINMETZ: DETERMINING PLOT YIELDS. 



91 



pressed in percentage which may be considered significant are 13.98 
and 15.16 percent respectively. For determinations from 10 square 
yards removed from each of 3 tenth-acre plots, 30 determinations in 
all, a difference between the yields of any two treatments of 9.60 per- 
cent appears to be significant. For the yield determination from the 
square yards removed from 3 tenth-acre plots of rye at St. Paul and 
oats at Duluth the significant differences are somewhat higher than 
where the yields from all square yards is considered. For the oats 
at Grand Rapids a dift'erence of 24.54 percent between the yields from 
any two treatments on 3 tenth-acre plots and a dift'erence of 36.35 
percent between any two treatments as determined from 4 square 
yards removed from 3 tenth-acre plots appear to be necessary in order 
to be reasonably certain that the increases are due to treatment. 

The increases in yield expressed in percentage over the check as 
determined from 3 tenth-acre plots and from 10, 9, 8, 5, and 4 square 
yards removed from each of 3 tenth-acre plots are given in Tables 5 
to 9 inclusive. The results for the determinations at each location 
are discussed separately for the reason that the soil at each point is 
more or less different. 

RESULTS WITH WHEAT AT THE MORRIS SUBSTATION. 

The increases in yield of wheat at the Morris substation due to fer- 
tilizer treatment expressed in percentage are given in Table 5. 

Table 5. — Comparison of the percentage increase in yields of wheat for each 
fertiliser treatment based on the mean yield of the check plots of Series 
II, III and IV at the Morris substation. 



Treatment. 



Increase percentages in yields as determined by harvesting — 



Three entire 



Stated number of square yards from each of three similarly treated 
tenth-acre plots. 





tenth-acre plots. 


10. 


9- 


8. 


5. 


4 at center. 


4 at ends. 


Series II: 
















A 


4-65 


3.26 


1.95 


3-28 






7-89 


B 


19.81 


34-64 


34-41 


35-53 


37-66 


44-74 


26.97 


C 


19.76 


39.22 


38.90 


33-00 


41.56 


43-42 


36.17 


D 


28.48 


37.26 


39-61 


38.82 


38.31 


43-42 • 


31-57 


E 


25.00 


27-45 


27.92 


26.32 


22.08 


^3-68 


29.60 


Series III: 










A 


7.74 


8.26 


5.65 


10.13 


14.10 


13-79 


6.61 


B 


16.83 


17.30 


15-32 


17.72 


17-94 


18.10 


17.36 


C 


19.86 


18.18 


15-32 


21.94 


23-93 


22.84 


21.49 


D 


31.65 


33.06 


29.84 


34-60 


32.48 


31-47 


38.02 


E 


29.29 


26.45 


21.37 


28.69 


26.90 


24.56 


33-06 


Series IV: 








A 


1. 10 


11.98 


13-23 


11.98 


12.83 


15-38 


11.00 


B 


6.13 


29.68 


29.63 


28.65 


27.69 


29.67 


29.50 


C 


5.75 


17.71 


20.11 


17-58 


20.32 


22.53 


14.50 


D 


15-33 


26.04 


25.90 


25-52 


29.40 


28.02 


24.00 


E 


7.66 


16.67 


18.52 


16.67 


22.99 


21.98 


13-50 



92 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Employing 13.98 percent as the least increase in yield over the 
check which may be considered significant, for the determinations 
from the tenth-acre plots all treatments except A may be considered 
as distinctly beneficial on Series II. Using 9.60, 10.09, 10.70, 13.05 
and 15.16 as the least increases in yield expressed in percentages as 
ascertained by removing 10, 9, 8, 5, and 4 square yards respectively 
from 3 tenth-acre plots, the results are practically the same as were 
secured from harvesting the entire plots. The percentage increases 
over that of the check, except for treatment E, are somewhat higher 
by the square yard than by the entire plot method. 

On Series III as on Series II each treatment, except treatment A, 
was effective by each of the two methods of determining yields. On 
each of the two series the yields from 4 square-yard areas removed 
from 3 tenth-acre plots indicated increases in yield due to treatments 
as effectively as the yields from the tenth-acre plots. On Series III 
treatments D and E may be considered to be superior to treatments 
A, B, and C. This is also broadly indicated by the yields from the 
10, 9, 8, and 4 square yards at the ends. 

On Series IV the yields from the entire plots indicate only treat- 
ment D as effective. The yield from the square yards except the 4 
at the ends indicate significant increases for all treatments. As indi- 
cated by lower probable errors, the yields from the 10, 9, 8, and 5 
square-yard areas removed from 3 tenth-acre plots may be considered 
more accurate than the yields from the 3 tenth-acre plots from which 
they were taken. This interpretation is supported by the fact that in 
1917 (i) treatments B, C, and D were effective by the yields from 
the 3 tenth-acre plots ; treatments B, C, D, and'E from the yields from 
the 9 and 5 square yards ; and treatments D and E by the yields from 
the 4 square yards removed from 3 tenth-acre plots. 

Treatments B, C, D, and E may be considered as giving significant 
increases in yield at Morris. 

RESULTS WITH WHEAT AND RYE AT UNIVERSITY FARM. 

The increases in yield over the check expressed in percentage for 
the wheat and rye at University Farm are given in Table 6. 

On Series IV none of the treatments appear to have produced sig- 
nificant increases in yield as ascertained from the tenth-acre plots. 
The yields from the square yards uniformly indicate increases in 
yield for treatments B, C, and D over the check. For the yields from 
the 10, 5, and 8 square yards removed from 3 tenth-acre plots, signifi- 
cant increases in yield are indicated for treatments B, C, and D over 
treatments A and E. 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 



93 



On Series V, the yields from the entire plots do not indicate signifi- 
cant increases in yield for any of the treatments. For treatments B, 
C, and D significant increases in yield are indicated from the lo and 
9 square yards and for treatments C and D by each number of square 
yards remioved from 3 tenth-acre plots. 

Table 6. — Comparison of the percentage increase in yields of wheat for each 
fertiliser treatment based on the mean yield of the check plots on Series 
IV and V and of rye on Series VII, University Farm, St. Paul. 



Increase percentages in yields as determined by harvesting — 



Stated number of square yards from each of three similarly treated 
tenth-acre plots. 





tenth-acre plots. 
















10. 


9- 


8. 


5. 


4 at center. 


4 at ends. 


Wheat on 
















Series IV: 
















A 


4-95 


4.48 


6.82 


3-82 


7.34 


6.II 


0.80 


B 


11.73 


18.28 


18.93 


22.14 


24.32 


23.28 


20.91 


C 


10.80 


18.65 


19.32 


22.14 


21.62 


21.00 


22.81 


D 


9.88 


18.28 


19.32 


19.46 


20.46 


18.70 


19.39 


E 


2.78 


4.85 


7.58 


7.25 


8.88 


6.11 


7.98 


W heat on 
















Series V: 
















A 


0.82 




.61 










B 


8.71 


10.87 


11.66 


9.00 


10.45 


7.12 


13.25 


C 


4.90 


18.13 


20.85 


16.57 


18.80 


18.60 


16.87 


D 


8.99 


1570 


16.87 


13.61 


14.53 


13.95 


16.00 


E 


4-63 


5-14 


5-83 


1.80 


.90 










Rye on 
















Series VII: 
















A 


13.57 


11.65 


12.26 


13.71 


15.35 


19.37 




B 


38.91 


31.07 


32.84 


34-35 


35.15 


36.14 


22.38 


C 


34-39 


28.64 


28.43 


36.55 


29.21 


30.69 


31.43 


D 


34.84 


40.29 


41.67 


48.73 


41.09 


43.56 


41.43 


E 


28.50 


- 33.50 


34.80 


38.07 


34.16 


35.64 


29.05 



The increases due to treatment on one series confirm that on the 
other, and support the conclusion that significant increases in yield 
were secured due to treatment which were not indicated by the yields 
from the entire tenth-acre plots. 

Using the percentage increases indicated in Table 4 for the rye on 
Series VII, it is evident that all treatments gave significantly increased 
yields as indicated both by harvesting the entire plots and by removing 
square-yard areas from them except in the case of the 4 square yards 
at the ends which do not indicate treatment A as being effective. 

The indications are that treatments B, C, D, and E are more effec- 
tive than treatment A by both methods. The increases in yields from 
the 10, 9, and 8 square yards indicate that treatment D is more effec- 
tive than treatment C. 

For the rye, significant increases were indicated for all treatments 



94 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



by both methods. By the removal of lO, 9, and 8 square yards from 
the 3 tenth-acre plots of the same treatment, it is possible to determine 
in this case which of the treatments is the best. This difference is not 
indicated by the yields from the entire plots. 

RESULTS WITH BARLEY AT WASECA. 

The percentage increases for various treatments applied to barley 
at Waseca are given in Table 7. 



Table 7. — Comparison of the percentage increase in yields of barley for each 
fertiliser treatment based on the mean yield of the check plots at 
Waseca substation. 



Treatment. 


Increase percentages in yields as determined by harvesting — 




Three entire 
tenth-acre 
plots. 


Stated number of square yards from each of the three 
treated tenth-acre plots. 


similarly 


.0. 


9- 


8. 


5- 


4 at center. 


4 at ends. 


A 


11.38 


6.29 


2.70 


7.28 


6.60 


12.42 


I.61 


B 


15.87 


12.26 


7.81 


12.97 


11.64 


11.49 


14.47 


C 


8.68 


8.18 


3-90 


8.00 


7-55 


r 3-11 


12.86 


D 


11-37 


10.38 


7.21 


10.76 


9.75 


13-04 


7.72 


E 




■ " - 













Significant increase in yield due to treatment is indicated for treat- 
ment B only by the entire plot method. The yields from the 10 and 
8 square yards indicate treatments B and D as effective. The yields 
from the 9 square yards removed from each of 3 tenth-acre plots do 
not indicate any of the treatments as effective. 

It may be concluded that on the barley at Waseca, treatments B 
and D were effective, only the former being indicated as superior to 
the check by the yields from the entire plots. 

RESULTS WITH OATS AT DULUTH. 

In Table 8 are given the increases in yield of oats at Duluth over 
the check by the two methods. 

Table 8. — Comparison of the percentage increases in yields of oats for each 
fertiliser treatment based on the mean yield of the check plots at the 
Duluth substation. 



Treatment. 



Increase percentages in yields as determined by harvesting- 



Three entire 
tenth-acre plots. 



Stated number of square yards from each of the three similarly 
treated tenth-acre plots. 



at center. 4 at ends. 



4.19 

10.40 
3-64 



13.38 
14-37 
16.73 
22.05 
17.32 



9.62 
11.92 
15.19 
15.77 
13.85 



13.53 
16.67 
16.86 
22.75 
10.59 



15.18 
22.67 
24.90 
23.68 
19.80 



13.02 
24.06 
20.51 

18.74 
21.89 



14-45 
9.57 
13.67 
27-15 
11.33 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 95 

Employing the percentage increases which seem necessary for sig- 
nificant effect of treatment at this location as given in Table 4, exami- 
nation of the increases in yield as indicated by the entire plots shows 
an approach to significant effect for treatment D only. 

From the square yards removed from each of 3 tenth-acre plots, 10 
indicate significant increases due to each treatment ; 9, 5, and 4 at the 
center indicate all but treatment A as eft'ective ; and 8, all but treat- 
ment E as effective. 

The results from the square yards in 19 18 confirm very closely the 
results obtained by the rod-row method at this location in 191 7. The 
conclusion is obvious that the 10, 9, 8, and 5 square yards removed 
from each of 3 similarly treated tenth-acre plots indicated significant 
increases not shown by the yields from the tenth-acre plots. 

RESULTS WITH OATS AT GRAND RAPIDS. 

The increases in yield of oats at Grand Rapids are given in Table 9. 



Table 9. — Comparison of the percentage increases in yields of oats for each 
fertiliser treatment based on the mean yield of the check plots at the 
Grand Rapids substation. 





Increase percentages in yields as determined by harvesting- — 


Treatment. 


Three entire 
tenth-acre 


Stated number of square yards from each of the three similarly 
treated tenth-acre plots. 




plots. 


,0. 


9- 


8. 


5- 


4 at center. 


4 at ends. 


A 
B 
C 
D 
E 


25.00 
28.80 
40.80 


6.71 
11.26 

37-37 
17.72 
7.19 


1.68 
8.89 
38.22 
17.30 


11.22 
10.49 
36.00 

14-39 


6.31 
28.60 

14-95 


13-47 
II. 17 

58.74 
33-60 

6.34 


9-57 
10.00 

19-57 
.60 













Using for the yields from the entire plots 24.54 as given in Table 4 
as the least percentage difference which is probably significant, the 
indications are that treatments B, C, and D were effective. 

Employing for the square yards the least percentage differences 
which are probably significant as given in Table 4 for the work at 
this location, treatment C appears to have been effective by the yields 
from all combinations of square yards except the 4 at the ends. 

Due to the unevenness of the stand of the oats on the plots at this 
location, it was difficult to secure representative samples and the vari- 
ability of the yields of the square yard areas was abnormally high. 

From the nature of treatments B, C, and D it is logical to expect 
that if one gives a significant increase in yield the other two will also. 



96 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Therefore, it may be concluded that 3 similarly treated tenth-acre 
plots were more efficient in indicating significant increases in yield at 
this location than 10 square yards removed from these plots. 

It appears fair to conclude that where the stands of crop are fairly 
uniform yields determined from 4 or 5 systematically distributed 
square-yard areas gives as accurate determinations of yield as har- 
vesting the tenth-acre plots from which the square-yard areas are 
taken. As probable errors for single determinations usually increase, 
under similar conditions, with the reduction in size of the plots, 4 or 
5 square-yard areas removed from plots less than one-tenth acre in 
size of relatively uniform crop can be substituted for the yields of the 
plots from which they are taken with still greater confidence than in 
the case of tenth-acre plots. 

Where the stands of the crop are relatively nonuniform due to 
variations in soil or water supply, the yields from 5 to 8 square-yard 
areas systematically distributed may be substituted safely for the 
yields from plots one-tenth acre in size or smaller. 

On plots or fields where stands are very nonuniform, due to winter- 
killing or to marked differences in soil or water supply, the yield from 
10 square-yard areas removed from tenth-acre plots may not be suffi- 
ciently accurate to substitute for the yield of the plots from which 
they were taken. 

Comparison of the Yields Secured from Tenth-Acre Plots and from 
Square Yard Areas Removed from Them. 

The yield from each tenth-acre plot and from the various combina- 
tions of square-yard areas removed from it are of interest chiefly 
from the standpoint of the technic of conducting plot tests. The 
yields of each three plots of any treatment with the mean as ascer- 
tained by the two methods are grouped in Tables 10, 11, and 12. 

Border Effect on Yields. 

Plots having alleys on the sides and separated by cultivated road- 
ways on the ends give higher yields than are secured from plots of 
the same size but not subject to border effect (2). 

All plots from which yields are given, except those at Grand Rapids, 
were separated by alleys on the sides and by roadways either culti- 
vated or in grass on the ends. No borders were removed from the 
plots separated by alleys. Therefore, except at Grand Rapids where 
the yields ascertained by the two methods may be expected to be 
approximately equal, the yields from the entire tenth-acre plot should 
ordinarily be approximately 5 to 10 percent higher than the yields 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 



97 



Table io. — Comparison of yields of Marquis wheat grown at the Morris sub- 
station under six different treatments as determined from triplicate 
tenth-acre plots and from lo, g, 8, 5 and 4 square yards removed 
from triplicate tenth-acre plots. 

SERIES II. 



Source 


Treat- 
ment. 


Yields in bushels 
per acre of trip- 
licate plots. 


Mean yield. 


Treat- 
ment. 


Yields in bushels 
per acre of trip- 
licate plots. 


]Mc3.n yield. 


Tenth acre 


Check 


18.2 


T7 7 


T ^ 7 


17.2 ±0.42 


c 


20.9 


21 Q 


18.9 


20.6io.49 


10 sq. yds. 




T ^ T 




T ^ /I 


T r* ^7 1 r\ r\f^ 

i5-3=to-OD 




2"^ 7 


18.8 


21 A 


21.3io.70 


9 sq. yds. 




T ^ T 


T 5 /I 

^0-4 


I 6 


15.4zto.08 




2% 8 


19.0 


21 


21.4io.76 


8 sq. yds. 






1 6.0 


T ^ 1 


15.2zho.27 




2'? A 


18 ^ 


22.0 


21.2io.84 


5 sq. yds. 




J A T 


ID./ 


T C 7 

^0-3 


15.4io.41 






19.0 


2T 1 


21.8io.98 


4 at cen. 




14.2 


16.4 


15.0 


15.2io.35 




24.0 


19-3 


22.0 


21.8io.75 


4 at ends 




14-3 




15-5 


15.2io.23 




22.9 


17.2 


22.1 


20.7io.98 


Tenth acre 


A 


17-5 


19.8 


16.7 


18.oio.51 


D 


22.9 


23-3 


20.0 


22.1 io. 57 


10 sq. yds. 




14.2 


16.4 


16.8 


15.8io.45 




I9.I 


25.9 


18.0 


21. oil. 36 


9 sq. yds. 




13.7 


16.4 


17.0 


15.7io.56 




19.4 


26.2 


18.8 


2i.5il.3i 


8 sq. yds. 




14.2 


16.0 


16.9 


15.7io.44 




18.7 


26.5 


17.4 


2O.9il.57 


5 sq. yds. 




131 


15.7 


16.6 


15.1io.58 




19-5 


26.6 


17.9 


2i.3il.47 


4 at cen. 




12.3 


16.0 


16.8 


15.oio.87 




19-5 


27.1 


18.8 


2i.8il.46 


4 at ends 




16.2 


I6.I 


16.9 


16.4io.16 




17.9 


25.9 


16.2 


20. Oil. 65 


Tenth acre 


B 


19.1 


23.5 


18.9 


20.5io.83 


E 


22.5 


21. 1 


20.9 


2i.5iO.27 


10 sq. yds. 




20.0 


22.7 


19.1 


20.6io.60 




20.1 


19.1 


19.2 


i9.5iO.l6 


9 sq. yds. 




19.6 


22.8 


19.8 


20.7io.57 




20.3 


19.4 


19.4 


i9.7iO.l6 


8 sq. yds. 




19.6 


23.2 


19.1 


20.6io.71 




20.3 


18.4 


19.0 


i9.2iO.3i 


5 sq. yds. 




20.2 


23.6 


19.9 


21.2io.65 




20.0 


18.2 


18.3 


l8.8iO.3i 


4 at cen. 




20.6 


24.0 


21.4 


22.oio.57 




19.9 


17.8 


18.6 


l8.8iO.35 


4 at ends 




18.6 


22.3 


16.9 


19.3io.88 




20.7 


19.0 


19.4 


i9.7iO.27 



SERIES III. 



Tenth acre 


Check 


27.8 


30.5 


30.9 


29.7io.54 


C 


34-4 


37-3 


35-1 


35.6io.48 


10 sq. yds. 




22.9 


22.5 


27.1 


24.2io.81 




29.6 


29.0 


27-3 


28.6io.39 


9 sq. yds. 




22.9 


23.0 


28.6 


24.8i1.04 




29.4 


29-3 


27.2 


28.6io.39 


8 sq. yds. 




22.3 


22.1 


26.8 


23.7io.85 




29-3 


29.9 


27.6 


28.9io.39 


5 sq. yds. 




22.3 


20.7 


27.1 


23.4i1.06 




30.1 


29.9 


27.0 


29.oio.55 


4 at cen. 




22.1 


20.6 


26.9 


23.2i1.05 




29.6 


30.0 


25-9 


28.5io.72 


4 at ends 




22.5 


23-5 


26.7 


24.2 io. 70 




28.9 


29.9 


29-3 


29.4io.16 


Tenth acre 


A 


30.9 


33-0 


32.0 


32.oio.35 


D 


40.0 


39-5 


37.8 


39.1io.35 


10 sq. yds. 




26.5 


26.4 


25.6 


26.2i0.16 




31-3 


33-8 


31-5 


32.2io.44 


9 sq. yds. 




26.3 


26.7 


25-6 


26.2 io. 19 




31.6 


33-7 


31.2 


32.2io.43 


8 sq. yds. 




26.7 


26.6 


25.0 


26.1 io. 31 




31.6 


33-0 


3I-I 


31.9io.31 


5 sq. yds. 




27.0 


26.2 


26.8 


26.7i0.12 




31.2 


31.2 


30.5 


31.oio.12 


4 at cen. 




28.3 


25-5 


25-5 


26.4i0.51 




31-5 


30.8 


29.2 


30.5io.39 


4 at ends 




25.1 


27.8 


24-5 


25.8io.56 




31-8 


35-3 


33-1 


33.4io.54 


Tenth acre 




33-9 


35-6 


34-6 


34.7io.27 


E 


37-8 


38.2 


39-1 


38.4io.20 


10 sq. yds. 


B 


27.2 


28.7 


29-3 


28.4io.35 




28.0 


32.8 


30.9 


30.6io.77 


9 sq. yds. 




27.1 


28.8 


29.8 


28.6io.43 




27.6 


32.3 


30.5 


30.1 io. 76 


8 sq. yds. 




27.0 


28.8 


27.8 


27.9io.27 




27.8 


32.9 


30.9 


3O.5iO.82 


5 sq. yds. 




26.4 


28.7 


27.7 


27.6io.35 




27.6 


32.1 


29.4 


29.7iO.72 


4 at cen. 


26.0 


28.6 


27-5 


27.4io.44 




26.3 


314 


29.0 


28.9iO.8l 


4 at ends 


j 28.2 


29.0 


28.1 


28.4i0.16 




29-3 


34-4 


32.9 


32.2iO.83 



98 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table 10. — Comparison of yields of Marquis wheat — Continued. 



SERIES IV. 



Source 


Treat- 
ment. 


Yields in bushels 
per acre of trip-, 
licate plots. 


IVIcRii yield. 


Treat- 
ment. 


Yields' in bushels 
per acre of trip- 
licate plots. 


JMean yield. 


Tenth acres 


Check 






28 1 
^o-3 


26.1 d=0.62 


c 


26 


26 2 


30-5 


27.6zbo.81 


10 sq, yds. 




18.8 


18. 1 


20.8 


19.2i0.44 




22.5 


18^6 


26.6 


22.6zbi.46 


9 sq. yds. 




18.6 


17.7 


20.4 


18.9zb0.44 




22.3 


19.0 


26.7 


22.7i1.23 


8 sq. yds. 




18.6 


18.0 


20.9 


19.2 ±0.49 




22.6 


18.2 


26.9 


22.6zbi.38 


5 sq. yds. 




18.3 


17.2 


20.5 


18.7db0.53 




21.6 


18.7 


27.2 


22.5zbi.38 


4 at cen. 




18.3 


I7.I 


19.2 


i8.2ibo.35 




21.7 


18.2 


27.1 


22.3ii.43 


4 at ends 




18.8 


18.8 


22.5 


20.0d=0.68 




23.6 


18.3 


26.8 


22 oil 'I'J 


Tenth acres 


A 








26.4io.64 


D 


3"-0 






3O.liO.74 


10 sq. yds. 




18.2 


20.4. 


2S.8 


21.5=bl.24 








2=; 7 


24.2 io. 70 


9 sq. yds. 




18.3 


20.2 


25.6 


2I.4±I.20 




23.0 


23.0 


25-3 


23.8io.44 


8 sq. yds. 




18. 1 


20.8 


25-7 


2I.5=bI.23 




22.9 


23.0 


26.4 


24.1 io.64 


5 sq. yds. 




16.9 


19.9 


26.6 


21.lrbl.58 




22.6 


22.6 


27-3 


24.2io.87 


4 at cen. 




18.0 


19.6 


25-3 


2I.0itI.22 




22.1 


20.9 


26.8 


23.3io.99 


4 at ends 




18.5 


22.1 


26.0 


22.2zbl.i9 




237 


24.6 


26.0 


24.8io.35 


Tenth acres 


B 


25-8 


28.0 


29.4 


27.7zbO.58 


E 


27.9 


24.9 


31-5 


28.IiI.05 


10 sq. yds. 




22.1 


24.8 


27.8 


24.9zbO.9i 




21. 1 


21.5 


24-5 


22.4io.59 


9 sq. yds. 




21.9 


24.7 


26.9 


24.5zbO.80 




21. 1 


21.4 


24.7 


22.4io.64 


8 sq. yds. 




21.8 


24.9 


27-5 


24.7zbO.9i 




21.3 


21.5 


24-5 


22.4io.57 


5 sq. yds. 




20.6 


23-7 


27-3 


23.9JzI.O7 




19.4 


23-5 


26.0 


23.oiI.06 


4 at cen. 




20.6 


23-7 


26.4 


23.6dzO.92 




19.0 


21.8 


25.9 


22.2iI.IO 


4 at ends 




22.9 


26.1 


28.7 


25.9iO.92 




23.6 


21.3 


23.1 


22.7iO.39 



Table ii. — Comparison of yields of Marquis wheat grown on Series IV and V 
and rye on Series VII at University Farm under six different treatments 
as determined from triplicate tenth-acre plots and from 10, p, 8, 5, 
and 4 square yards removed from triplicate tenth-acre plots. 

SERIES IV. 



Source. 


Treat- 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 


Treat- 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 


Tenth acres 


Check 


29.7 


30.5 


37-1 


32.4il.29 


c 


34.6 


39-0 


34-2 


35-9±o.85 


10 sq. yds. 




24.4 


24.7 


31.4 


26.8il.26 




29.8 


33.8 


31.8 


31.8io.64 


9 sq. yds. 




23.6 


24.6 


3I-I 


26.4iI.3O 




29-5 


33-3 


31.6 


31.5io.61 


8 sq. yds. 




23.8 


237 


31.1 


26.2il.35 




30.5 


33-6 


31.8 


32.oio.50 


5 sq. yds. 




22.1 


23-5 


32.1 


25.9il.72 




30.2 


32.0 


32.3 


3i.5=bo.35 


4 at cen. 




22.2 


24.2 


32.1 


26.2il.67 




30.0 


314 


33.8 


31.7io.61 


4 at ends 




25-3 


23-3 


30.2 


26.3il.i3 




31.0 


35-9 


29.9 


32.3i1.02 


Tenth acres 


A 


30.2 


32.8 


390 


34.OiI.49 


D 


34-3 


37-9 


34-5 


35.6io.64 


10 sq. yds. 




25-1 


25-3 


33-6 


28.OiI.56 




29-5 


34-8 


30.8 


31.7io.88 


9 sq. yds. 




25.2 


25.6 


33-8 


28.2il.33 




28.8 


344 


31-3 


31.5io.89 


8 sq. yds. 




23.1 


24.9 


33.5 


27.2il.77 




28.5 


34-9 


304 


31.3i1.04 


5 sq. yds. 




23.8 


25-5 


34-2 


27.8il.77 




29.4 


33-8 


30.3 


31.2io.73 


4 at cen. 




23.8 


25.6 


34-0 


27.8il.73 




29.2 


32.9 


31-3 


31.1io.59 


4 at ends 




22.3 


24 2 


33-0 


26.5il.82 




27.7 


37-1 


29-5 


31.4i1.59 


Tenth acres 


B 


32.9 


39-1 


36.6 


36.2iO.99 


E 


31.5 


34-9 


334 


33.3io.54 


10 sq. yds. 




29.8 


35-0 


30.3 


3i.7iO.9i 




25.2 


29.5 


29.6 


28.1io.80 


9 sq. yds. 




29.8 


34-5 


29.9 


31.4^0-85 




25-3 


30.1 


29.9 


28.4io.87 


8 sq. yds. 




29.0 


357 


31-3 


32. Oil. 08 




24.0 


29.6 


30.6 


28.1i1.13 


5 sq. yds. 




28.9 


357 


31-9 


32.2il.08 




22.9 


31.0 


30.8 


28.2i1.47 


4 at cen. 




28.2 


36.4 


32.2 


32.3il.3i 




23-3 


30.2 


29.9 


27.8i1.24 


4 at ends 




29.9 


35-1 


30.3 


3i.8iO.93 




24.7 


29.2 


314 


28.4i1.09 



ARNY & STEIXMETZ: DETERMINING PLOT YIELDS. 



Table ii. — Comparison of yields of Marquis zchcat — Continued. 

SERIES V. 



Source. 


Treat- 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mca.n yield. 


Treat- 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 




Tenth acres 




Check 


37-1 34-5 


38.6 




36.7 ±0.66 


c 


37-8 


35-5 


42.3 


38.5dzI.IO 


lo sq. yds. 




34-8 31-4 


33-1 


33.1 ±0.54 




38.8 


40.6 


37-9 


39.1 zfcO.44 


9 sq. yds. 




34.2 31,2 


'O 


32.6zbo.48 




^8.9 


40. 


38.8 


39.4dzO.3i 


8 sq. yds. 




35.71 32.7 




33.8 ±0.53 






4.1.4 




39.4d1O.67 


5 sq. yds. 




35.8' 32.7 


^2.1 


33.5zto.63 






4.2.0 


37.8 


39.8dzO.67 


4 at cen. 




36.1 32.4 




33.7zfco.67 




-^9.6 


4-2.0 




4O.Od1O.88 


4 at ends 




35.4 30.6 

i 


33.6 


33.2zfco.77 




Oy'O 


40.2 


37.0 


38.8dzO.53 


Tenth acres 


A 


35.5' 37.1 


38.3 


37.ozfco.45 


D 


38.4 


38.6 


42.9 


4O.OzfcO.8l 


10 sq. yds. 




32.6 34.4 


31-8 


32.9io.42 




37-0 


40.5 


37.3 


38.3dzO.62 


9 sq. yds. 




32.6 34-3 


314 


32.8dzo.46 




36.9 


40.6 


36.7 


38.1 zfcO.70 


8 sq. yds. 




32.5 35.2 


31-8 


33.2dzo.57 




37-5 


40.8 


37.0 


38.4dzO.66 


5 sq. yds. 




30.8 36.7 


32.4 


33.3dzo.97 




37-6 


40.7 


37-0 


38.4zfcO.65 


4 at cen. 




32.1 36.0 


31.8 


33-3±o.74 




36.8 


41.4 


37-0 


38.4dzO.83. 


4 at ends 




32.9 34-4 


31.9 


33.1 ±0.40 




38.2 


40.1 


37-1 


38.5zfcO.48 


Tenth acres 


B 


37.9 40-2 


41-5 


39.9io.58 


E 


32.8 


39-7 


42.7 


38.4zfcl.6l 


10 sq. yds. 




32.81 41. 1 


36.2 


36.71fc1.33 




28.0 


39-1 


37-4 


34.8 db 1. 90 


9 sq. yds. 




32.0! 41.5 


35.8 


36.4dzi.52 




28.1 


38.7 


36.7 


34.5dzl.34 


8 sq. yds. 




32.9 41.2 


36.4 


36.8i1.32 




27.4 


38.5 


37.4 


344±i-33 


5 sq. yds. 




32.4 42.3 


36.4 


37.oi1.59 




27.4 


37.7 


36.4 


33.8dzi.78 


4 at cen. 




30.8 42.0 


35-4 


36.1 ±1.79 




25-9 


37-2 


35.7 


32.9 ±1.34 


4 at ends 




34-9i 40.4 


37-4 


37.6d1O.88 




29.0 


39-9 


39-1 


36.0 dz 1. 93 



SERIES VII. 



Tenth acres 


Check 


24.6 


20.9 


20.7 


22.1 dzo.70 


C 


29.8 


29.6 


29.8 


29.7dzO.04 


10 sq. yds. 




21.4 


151 


25-3 


20.6zfc1.64 




22.8 


28.1 


28.6 


26.5dzi.02 


9 sq. yds. 




21.9 


13.6 


25.6 


20.4zfc1.96 




22.4 


28.4 


27.8 


26.2zfc1.05 


8 sq. yds. 




22.0 


14.9 


22.2 


19.7zfc1.32 




23.1 


28.5 


29.2 


26.9dzi.06 


5 sq. yds. 




21.5 


13-8 


25.2 


20.2zfc1.85 




22.6 


28.8 


26.9 


26.1 dzI.OI 


4 at cen. 




21.5 


12.9 


25.8 


20.1 zfc2.09 




22.2 


29.0 


27.7 


26.3dzl.i5 


4 at ends 




22.6 


16.9 


23-5 


2i.OzfcI.i4 




24.0 


27.9 


30.8 


27.6dzI.O9 


Tenth acres 


A 


26.7 


25.1 


23.6 


25.ldzO.5O 


D 


314 


257 


32.2 


29.8dzl.i3 


10 sq. yds. 




20.1 


23.0 


25.8 


23.0zfc0.91 




27.7 


27.6 


31.5 


28.9dzO.7i 


9 sq. yds. 




19.4 


22.8 


26.4 


22.9dzI.II 




27.7 


27.8 


31.2 


28.9ztO.64 


8 sq. yds. 




193 


22.3 


25-5 


22. 4zfcO. 96 




28.3 


28.1 


31-5 


29.3ztO.6l 


5 sq. yds. 




20.1 


22.4 


27.4 


23.3dzl.i9 




26.2 


27.6 


31.7 


28.5dzO.9i 


4 at cen. 




21.0 


23.2 


27.8 


24.OzfcI.IO 




26.8 


27.7 


32.2 


28.9ztO.92 


4 at ends 




20.2 


21.4 


23-3 


2i.6zfcO.5O 




29.9 


28.4 


30-9 


29.7ztO.4O 


Tenth acres 


B 


31.0 


30.3 


30.8 


3O.7dbO.i2 


E 


28.5 


26.7 


30.0 


28.4d1O.53. 


10 sq. yds. 




27.1 


26.4 


27.4 


27.OdzO.l6 




24.6 


25-8 


32.0 


27.5ztl.26 


9 sq. yds. 




27.1 


26.4 


27.8 


27.1 dzO.23 




24.8 


25-9 


31.8 


27.5ztl.2O 


8 sq. yds. 




26.9 


26.4 


26.3 


26.5dzO.i2 




23.8 


26.3 


31-5 


27.2ztl.25 


5 sq. yds. 




28.6 


25-5 


27.9 


27.3d1O.52 




23-5 


26.3 


31.4 


27.1 ztl.27 


4 at cen. 




29.1 


259 


27.1 


27.4zfcO.5i 




24.0 


26.3 


31-5 


27.3ztl.22 


4 at ends 




24.7 


26.9 


25-5 


25.7ztO.35 




23.6 


26.3 


31.5 


27.Id1I.28 



100 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 12. — Comparison of yields of Manshury barley grown at Waseca and 
Improved Ligowa oats grown at Duluth and Grand Rapids under six 
different treatments at determined from triplicate tenth-acre plots 
and from 10, g, 8, 5, and 4 square yards removed from tripli- 
cate tenth-acre plots. 



BARLEY AT WASECA. 



Soui ce. 


Treat- 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 


Treat- 
ment. 


Yield in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 


Tenth acres 


Check 


32-3 


34-8 


33-0 


33.4±o.4i 


C 


38.5 


38.9 


31-5 


36.3zbl.32 


10 sq. yds. 




30-5 


32.3 


32.6 


31.8dzO.35 




35-7 


36.3 


31. 1 


"^d.dzbO.QI 


9 sq. yds. 




31.2 


32.3 


32.7 


32.3rbo.23 




36.0 


36.4 


31-3 


34.6dbO.9O 


8 sq. yds. 




304 


32.5 


32.0 


31.6zbo.35 




34-7 


37-9 


29.7 


34.1 ztl.S"^ 


5 sq. yds. 




31-5 


32. » 


31.2 


31.8zbo.27 




34-1 


39-5 


oft n 
20.9 


34.2ztl.59 


4 at cen. 




30.3 


34-7 


31.6 


32.2zbo.72 




33-7 


37-4 


28.5 


33.2ztl.42 


4 at ends 




30.5 


30-3 


32.4 


31. 1 zbo.35 




35-8 


38.6 


31.0 


35.1 zbl.22 


Tenth acres 


A 




33-5 


40.9 


37-2zbi.44 


D 


39-0 


41.2 


31-5 


37.2zbi.66 


10 sq. yds. 




31-5 


32.3 


37-7 


33.8zb1.07 




34-1 


39-0 


32.1 


35-i±i.i3 


9 sq. yds. 




32.3 


32.4 


37-8 


34.2zb1.00 




35-0 


39-1 


33-0 


35-7±o.99 


8 sq. yds. 




31-9 


32.0 


37.8 


33.9±i.o8 




33-3 


38.9 


32.7 


35.0 dz 1. 09 


5 sq. yds. 




31.0 


31-9 


38.9 


33-9±o.43 




33-6 


39-0 


32.0 


34.9zb1.16 


4 at cen. 




34-6 


34-8 


39-2 


36.2zbo.83 




35-5 


40.4 


33-3 


36.4zb1.16 


4 at ends 




29.1 


29.2 


36.4 


31.6db1.33 




31.2 


37-3 


32.0 


33.5zb1.06 


Tenth acres 


B 


38.0 


36.5 


41.7 


38.7io.85 


E 


31-7 


32.1 


27-3 


30.4zbo.85 


10 sq. yds. 




36.7 


34-7 


35-7 


35.7zbo.31 




27.6 


31-5 


29.9 


29.7zto.62 


9 sq. yds. 




36.5 


34-9 


36.2 


35.91to.27 




27.7 


32.5 


29.9 


30.Ozto.76 


8 sq. yds. 




37-7 


34-7 


34.8 


35.7zbo.54 




27.2 


31.6 


29.9 


29.6zto.71 


5 sq. yds. 




36.0 


35-9 


34-6 


35.51bo.23 




27.1 


32.9 


29.7 


29.9zbo.92 


4 at cen. 




37-6 


36.7 


33-5 


35.9dbo.69 




28.0 


32.9 


29-5 


30.1 zbo.80 


4 at ends 




37-9 


32.7 


36.2 


35.6zto.85 




26.4 


30.3 


30.5 


29.1 zto.74 



OATS AT DULUTH. 



Tenth acres 


Check 


36.9 


54-3 


554 


54.9zbo.23 


C 


60.1 


45-5 


54-4 


53.3i2.34 


10 sq. yds. 




44.2 


49-5 


58.8 


50.81t2.35 




57.0 


64.9 


55-9 


59.3zb1.56 


9 sq. yds. 




46.3 


50.0 


59.6 


52.Ozt2.19 




56.6 


66.7 


56.3 


59.9±i.88 


8 sq. yds. 




43-9 


474 


61.6 


51.Ozt2.98 




57.2 


65.1 


56.5 


59.6d1i.52 


5 sq. yds. 




39.7 


47.2 


61.3 


49.4zb3.49 




55.9 


68.8 


60.4 


61.7zt2.09 


4 at cen. 




42.0 


47.8 


62.3 


50.7zt3.33 




51.5 


73-0 


58.9 


61. 1 ±3.47 


4 at ends 




45-7 


47.0 


61.0 


51.2zb2.70 




63.0 


57.3 


54-2 


58.2zb1.42 


Tenth acres 


A 


55-1 


56.6 


50.6 


54.izbo.99 


D 


58.0 


56.4 


67.4 


60.6zb1.89 


10 sq. yds. 




59-8 


527 


60.3 


57-6+1.35 




56.8 


58.1 


71. 1 


62.0 + 2.51 


9 sq. yds. 




58.3 


51.8 


61.0 


57.Ozb1.50 




55.2 


58.6 


66.9 


60.2dzi.91 


8 sq. yds. 




60.6 


52.1 


61. 1 


57.9±i-6i 




55.0 


58.4 


74-5 


62.6dr3.31 


5 sq. yds. 




54-4 


53-8 


62.4 


56.9zb1.53 




54-7 


58.9 


69.5 


61.izb2.43 


4 at cen. 




58.8 


55.6 


57-5 


57-3±o.5i 




53-5 


59-9 


67.2 


6o.2zb2.l8 


4 at ends 




62.5 


48.6 


64.8 


58.6±2.79 




56.6 


57-0 


81.7 


65.ldz4.57 


Tenth acres 


B 


57.8 


57-3 


56.5 


57.2zbo.20 


E 


53.4 


53-3 


64.1 


56.9zbl.97 


10 sq. yds. 




58.8 


58.6 


57-0 


58.1dzO.31 




57.5 


52.6 


68.6 


59.6dz2.6i 


9 sq. yds. 




58.1 


60.4 


56.0 


58.2zbo.70 




57-5 


53-5 


66.5 


59.2dz2.12 


8 sq. yds. 




62.7 


60.9 


54-8 


59.5zb1.32 




54.6 


53.6 


61. 1 


56.4dzi.30 


5 sq. yds. 




58.9 


68.4 


54-5 


60.6zb2.26 




57.3 


.52.7 


67.6 


59.2dz2.43 


4 at cen. 




62.0 


72.3 


544 


62.9d12.86 




58.1 


56.7 


70.6 


61.8dz2.43 


4 at ends 




634 


49.6 


55-2 


56.izb2.21 




51.0 


50.6 


69.4 


57.Ozt3.42 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. lOI 
Table 12. — Comparison of yields of barley and oats — Continued. 



OATS AT GRAND RAPIDS. 



Source. 


Treat 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 


Treat- 
ment. 


Yields in bushels 
per acre of tripli- 
cate plots. 


Mean yield. 


_ — 

Tenth acres 


Check 


27 7 


31-3 


28,5 


29.2 ±0.60 


c 




3-^'9 


17 7 


- - 

37-6±i.48 


10 sq. yds. 




45-5 


45.8 


33-8 


4i.7=t2.i8 




63.4 


48.3 


60.2 


57-3±2.53 


9 sq. yds. 




47.4 


43-8 


33-7 


41.6zh2.26 




66.7 


45.6 


60.3 


57-5±3-44 


8 sq. yds. 




4U.U 


45.5 


31-5 


41.O1t2.62 




04.7 


45-7 


0'-'-9 


55-8±3.04 


5 sq. yds. 




Q 


49.2 


33-4 


42.8zh2.65 






48.8 


AC\ A 

49-4 


55-1 ±3-33 


4 at cen. 




A2 Q 


39-8 


22.0 


34-9±3-59 




6=; 7 


v)^'4 




55.4zh2.85 


4 at ends 




AO T 


5I-I 


40.9 


47.Ort1.72 




6^ 6 


41 .0 


"3-9 


56.2zh4.l8 


Tenth acres 


A 


28.8 


27.8 


28.4 


28.3zho.16 


D 


49-0 


35-0 


30-9 


41. 1 ±2.39 


10 sq. yds. 




48^0 


43.4 


42.1 


44.5zho.99 




SI 8 


4.4.. Q 


50.6 


49i±i.i7 


9 sq. yds. 




46.2 


42.0 38.8 


42.3i1.18 




53-5 


42.3 


50-5 


48.8zh1.84 


8 sq. yds. 




49.1 


44.8I 42.8 


45.6±i.02 




47.2 


45-8 


47-7 


46.9zho.31 


5 sq. yds. 




47-3 


47.3 


41.9 


45.5 ±0.99 




56.3 


51-5 


39-9 


49.2zh2.68 


4 at cen. 




44-3 


48.9 


25-7 


39.6i3.89 




50.5 


48.0 


41.2 


46.6zh1.53 


4 at ends 




53.8 


40.8 


59-9 


5i-5±3.io 




44.0 


43-7 


54-2 


47.3i1.30 


Tenth acres 


B 


44.0 


31.8 


33-6 


36.5zt1.36 


E 


30.8 


22.5 


33-8 


29.oi1.86 


10 sq. yds. 




55-3 


40.0 


43-8 


46.4zh2.53 




40.8 


28.4 


47.0 


38.7i1.93 


9 sq. yds. 




54-8 


37-9 


43.1 


45-3±2.75 




40.9 


27.0 


46.2 


38.oi3.15 


8 sq. yds. 




54-9 


37-5 


43.4 


45-3±2.8i 




41.0 


27.8 


50.7 


39.8i3.66 


5 sq. yds. 




51-2 


38.4 36.5 


42.0zh2.54 




43-5 


24.7 


47.8 


38.7i3.89 


4 at cen. 




55-4 


34-8 


26.3 


38.8zh4.76 




39-3 


24.9 


47-1 


37.1i3.58 


4 at ends 




54-5 


40.1 


60.6 


5i.7±3-35 




42.7 


30.8 


54-3 


42.6i3.74 



from the square yards which were not subject to border effect (2). 
Where the yields from the plots are more than approximately 5 to 10 
percent higher than the yields from the yards, the difference may be 
due in part to the lower moisture content of the grain from the yards 
at the time it was weighed or to the actual size of the plots being 
somewhat greater than their computed area. On the other hand, 
where the yields of the plots are considerably lower than those from 
the square yards, it may be assumed that the grain from the plots was 
lower in moisture content than that from the square yards at the 
time each was weighed ; that more than ordinary losses were sustained 
in harvesting and thrashing the product from the entire plots ; or 
that the actual size of the plot was less than the computed size. The 
effect in any particular instance may be due to a combination of these 
causes. 

At Morris the plots are separated by cultivated alleys and the series 
by cultivated roadways. Throughout the latter part of the growing 
season and at harvest the plots on Series II showed a marked border 
effect and those on the other two series only moderate increased 
growth in the border areas. Comparison of the yields from the tenth- 
acre plots on Series II with those from the square-yard areas removed 



I02 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

from them indicates slightly greater than ordinary border effect for 
the check and treatment A, ordinary border effect for treatments D 
and E, and none for treatments B and C. Since the grain in all. the 
plots appeared to be equally affected by the alleys, some difference in 
size or method of handling the entire plot probably accounts for the 
lack of agreement between plots and yard yields in some instances. 
On Series III and IV where normal increases in yield due to border 
effect might be expected, the yields from the tenth-acre plots are from 
approximately 12 to 25 percent higher than the yields from the square- 
yard areas removed from them. Differences in the moisture content 
of the grain from the plots and square yards may account for this to 
some extent. 

At University Farm on Series IV the yields indicate greater in- 
creases in some cases than can be attributed to border effect. On 
Series V the middle plot of each three for treatments B, C, and D 
was very badly lodged at harvest. The unavoidable losses during 
harvest account definitely for the lower yields from the entire plots 
than from the square yards removed from them. 

On Series VII out of a total of 18 plots, 7 yielded lower from the 
entire areas than from the square yards removed from them. The 
loss in harvesting and thrashing the rye crop was practically negligible. 
On this series 7 plots yielding lower than the square-yard areas re- 
moved from them were probably slightly smaller than the computed 
size. 

For tlie barley at Waseca no yield was recorded from the first plot 
of treatment A by the entire plot method. The first plot for treat- 
ment B and the third plot for treatment E are considerably lower in 
yield as determined from harvesting the entire plots than is indicated 
from the square yards. The determinations of yields by each com- 
bination of square yards agree very closely and are probably more 
nearly correct than those from the plots. For the other plots the re- 
lation between plot and yard yields is approximately normal. 

At Duluth the first plot of the checks was injured by livestock after 
the square yards had been removed and, therefore, the yield is not 
used. For 8 of the 18 plots the yields from harvesting the entire 
areas is lower than from the square yards. Such differences in yield 
by the two methods as are indicated for the middle plot of treatments 
B, C, and D can be accounted for by assuming that some irregularity 
occurred on these plots. 

At Grand Rapids the entire series was sown solid and the oats occu- 
pying the alleys between plots was discarded at harvest. The roads 



ARNY & STEINMETZ: DETERMINING PLOT YIELDS. 



103 



surrounding the series are seeded to grass, which observations indi- 
cate depresses somewhat rather than increases yield in the end border 
areas. Here, then, the yields of the plots and from the square-yard 
areas removed from them may be expected to closely approximate 
each other. Inspection of the yields shows those from the entire 
plots very much lower in every instance, the difference amounting to 
over 20 bushels for individual plots, than from the square yards re- 
moved from them. These wide differences on practically all of the 
plots can be accounted for only by the actual size of the plots being 
considerably smaller than the computed size. 

These differences emphasize the necessity of exercising the greatest 
care in all operations in determining yield on plots in order that de- 
pendable results may be obtained. Particular attention appears to be 
necessary in the seeding operation so that the plots may be sown uni- 
formly to the exact desired width and more than full length so that 
they may be trimmed to the exact length. Sowing the plots long and 
trimming them to exact length at heading time obviates border effect 
on the ends which may raise or lower plot yields. Stretching a wire 
across each end of the plots in a series marking the exact length 
of the plots at the time the crop is i to 2 inches high and anchor- 
ing it firmly at frequent intervals permits the removal of the end 
borders very accurately and easily after the grain has headed out. 
Sowing the alleys between plots and removing the crop from them 
before harvest in such a way that the plots are left the exact width 
thruout is very good practice. From plots separated by alleys, the 
removal of an area 12 inches in width from either side of each plot 
largely obviates border effect (2). The removal of the border areas 
at any time between full heading and harvest is known to be a safe 
practice. How much earlier they can be removed and still secure the 
desired results is not known. 

Cost of Determinations of Yield by the Removal of Square- Yard Areas. 

The cost of determination of yield by the removal of 9 or 10 square- 
yard areas from plots is approximately the same as harvesting the 
entire areas with the binder and thrashing the grain with the ordinary 
thrashing machine (i). 

Summary. 

I. Probable errors in percentages of the mean for single determina- 
tions derived from the yields of 106 pairs of tenth-acre plots in 1918 
and 168 in 1917 and from the yields of 1,073 pairs of square-yard 
areas in 1918 and 432 in 1917 were 4.82, 5.35, 11.52, and 9.98, re- 



104 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

spectively. These probable errors are very similar to those given by 
other investigators for the same or similar sizes of plots. 

2. The calculated probable errors in percentages of the mean 
squared for the yield from single determinations on the tenth-acre 
plots (2X8 rods) varied from 4.35 to 11. 14 according to location. 
When the yields from the 160 tenth-acre plots are considered the cal- 
culated probable error in percentage of the mean squared for the 
yield from single determinations is 6.35. For this size of plot in 1917 
the variation in percentage was from 4.79 to 14.74, and, when all plots 
were considered, it was 7.12 percent. 

3. For the systematically distributed square-yard areas removed 
from each of 3 tenth-acre plots of similar treatment, the calculated 
probable error in percentage of the mean squared for yield from single 
determinations varied from 10.52 to 33.00 according to location. 
Considering the yields from 1619 square-yard areas, the calculated 
probable error in percentage of the mean squared for the yield from 
a single determination is 13.75. 

For rod rows, 16.5 feet by 6 inches, which are slightly smaller than 
a square yard, in 191 7 the variations in percentage were 9.95 to 16.83 ; 
and when all the rod rows were considered, the percentage was 12.93. 

4. Comparison of the probable errors for single determinations of 
yield from tenth-acre plots and square-yard areas indicates that 4 to 
5 systematically distributed square-yard areas removed from tenth- 
acre plots of relatively uniform standing grain give approximately 
the same probable error for yields as harvesting the products of the 
entire plots. 

When the stands of grain were relatively nonuniform, 5 to 10 sys- 
tematically distributed square-yard areas were necessary to reduce 
the probable errors to approximate those for the yields from the 
tenth-acre plots from which the square-yard areas were taken. 

5. Considering the significant percentage increases in yield for the 
various treatments as indicated by the yields from the tenth-acre plots 
and from the square yards removed from them indicates that, where 
the crop is relatively uniform, the yields ascertained from 4 to 5 sys- 
tematically distributed square yards may be safely substituted for the 
yields of the plot from which they are taken. 

Also, when stands of the crop are relatively nonuniform, 5 to 8 
square yards systematically distributed may be depended upon to give 
as accurate determinations of yields as the tenth-acre plot from which 
they were taken. 

Where the crop in plots or fields is very nonuniform due to winter- 



ARNY & STEIN:\IETZ : DETERMINING PLOT YIELDS. I05 

killing or to marked differences in soil or water supply, the yields 
from 10 systematically distributed square yard areas may not give a 
sufficiently accurate determination of yield to be able to substitute it 
with confidence for the yields of the plot or field from which they 
were taken. 

6. Dift'erences between the yields of individual plots other than 
what may properly be attributed to border effect emphasizes the ne- 
cessity of greater accuracy in all operations in connection with plot 
test work. 

7. Yields from as low as 4 and up to 10 square-yard areas sys- 
tematically distributed over 3 tenth-acre plots of similar treatment 
indicate that reliable determinations can be made from areas as small 
as /4840 acre in size, the number of areas used depending upon the 
degree of accuracy required. 

8. The cost of removing 10 square-yard areas from a tenth-acre 
plot, thrashing, and weighing the product, is approximately the same 
as for harvesting the entire area with the binder, thrashing the grain 
with the ordinary thrashing machine, and w^eighing the product. 

Conclusions. 

1. The variation in the calculated probable error for the yield de- 
terminations at the different locations emphasizes the desirability of 
deriving probable error for use in the interpretation of the results of 
each test. The pairing method may be used to advantage in deriving 
probable error where the yields from a sufficient number of check 
plots is not available for this purpose. 

2. Yields determined from 4 to 5 systematically distributed square- 
yard areas removed from plots one-tenth acre in size or less of rela- 
tively uniform crop may be confidently substituted for those from 
the entire plots. Under similar circumstances the yields from a 
greater number of square-yard areas may be considered more accu- 
rate than those from the entire plots. From very nonuniform crops 
the yield from 10 square-yard areas systematically distributed may 
not be as accurate as the yields from the entire plots. 

3. The method of determining yields by the removal of relatively 
small systematically distributed areas, square yards or rod rows, from 
plots may be used to advantage : 

(a) Where facilities for making yield determinations from entire 
plots are lacking ; 

(b) to check the accuracy of yield determinations on plots; 

(c) where more accurate determinations of yield are desired than 



I06 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

can be secured from the limited number of larger plots than can ordi- 
narily be devoted to a series of tests. 

Literature Cited. 

1. Arny, a. C, and Career, R. J. Field technic in determining yields of plots 

of grain by the rod-row method. In Jour. Amer. Soc. Agron., ii, no. i, 
p. 33-47. 1919- 

2. Arny, A. C, and Hayes, H. K. Experiments in field technic in plot tests. 

In U. S. Dept. Agr. Jour. Agr. Research, 15, no. 4, p. 251-262. 1918. 

3. Hayes, H. K., and Arny, A. C. Experiments in field technic in rod-row 

tests. In U. S. Dept. Agr. Jour. Agr. Research, 11, no. 9, p. 399^419. 1917. 

4. Kiesselbach, T. a. Studies concerning the elimination of experimental 

error in comparative crop tests. Nebr. Agr. Expt. Sta, Research Bui. 13, 
p. 1-95. 1918. 

5. McCall, a. C. a new method of harvesting small grain and grass plots. 

In Jour. Amer. Soc. Agron., 9, 138-140. 1917. 

6. Pearl, Raymond, and Miner, John Rice. A table for estimating the prob- 

able significance of statistical constants. Maine Agr. Expt. Sta. Bui. 226, 
' p. 85-88. 1914. 

7. Wood, T. B., and Stratton, F. J. M. The interpretation of experimental 

results. Ill Jour. Agr. Sci., 3, 415-440. 1910. 



A REASON FOR THE CONTRADICTORY RESULTS IN CORN 

EXPERIMENTS/ 

Lyman Carrier. 

introduction. 

The improvement of corn has been the aim of the wisest agricul- 
turists of the United States for many years. Our annual production 
is about I acre of corn for every man, woman, and child in the coun- 
try. It easily ranks first of all crops grown in America, both in pro- 
duction and total value. Any improvement in methods of growing 
the crop or in the inherent character of the corn itself which is re- 
flected in a generally increased yield, adds millions of dollars to our 
agricultural wealth. 

It would be interesting to know to what extent corn growing has 
been improved in the three centuries since the settlement of James- 
town and Plymouth. This is not easily determined. The early ex- 

1 Contribution from the Bureau of Plant Industry, United States Department 
of Agriculture, Washington, D. C. Publication authorized by the Secretary of 
Agriculture. Presented at the eleventh annual meeting of the American So- 
ciety of Agronomy, Baltimore, Md., January 7, 1919. 



carrier: results in corn experiments. 



107 



plorers described the corn plant quite fully, and their several accounts 
in the main agree. They rarely gave the yields stated in terms of 
units of land area, and when they did so state them the distinction 
was not made between shelled corn and corn on the cob. They usually 
stated the yield in terms of the quantity of seed planted. Land was 
too plentiful to be worthy of consideration. 

From a careful study of these early descriptions it appears safe to 
say that both the quality and yields of the corn grown by the Indians 
along the Atlantic Coast at the time of the English settlements would 
compare quite favorably with those of the average farmer in those 
sections to-day, tho probably somewhat inferior to the best improved 
strains grown now by the best farmers. Horse labor and machin- 
ery have been substituted for much of the hand labor performed 
by the Indians with clam shells and crooked sticks ; otherwise the 
methods of culture are almost identical with those taught by Kemps 
and Tassore, two " fettered Indian prisoners," to the colonists at 
Jamestown, and by Squanto, the friend of the Pilgrims at Plymouth. 
The Indians had developed types of corn suitable to the varied soil 
and climatic conditions of America, such as the flints for the North, 
prolifics for the South, and dents for the corn belt, which the white 
farmers in three centuries have not been able to improve. The work 
of the American Indians with this crop is nothing short of wonderful. 
We have accepted and practice by necessity their methods of culture. 
It appears now that it would be a wise course to adopt some of their 
breeding methods as well. 

DEVELOPMENT OF IMPROVED VARIETIES. 

Efforts at improvement of corn have led to the establishing of a 
number of quite definite varieties. These varieties, while showing 
marked differences in characteristics of the ears in the country as a 
whole, are quite similar for the regions where they were originated. 
That is, there is a strong similarity in general type among the im- 
proved flint corns in the Northern States, among the improved dent 
corns in the North Central division of States, among the prolific corns 
of the South, and among the single-eared varieties of the Southwest. 
While this shows that no one variety is suitable for the whole country, 
it indicates that there is a type based on ear characteristics which is 
best for each region. Some of these varieties have taken the name of 
the community in which they first became known, as Johnson County 
White and Boone County White, while others carry the name of the 
originator, as Leaming, Reid Yellow Dent, and Cocke Prolific. The 



I08 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

history of any one of these varieties, so far as it is known, usually 
traces ba-ck to the work of some one farmer. The procedure was cus- 
tomarily as follows : A farmer with a definite ideal in mind began 
systematically to select seed corn. In the course of a few years his 
yields were larger than those of other farmers in his community. His 
corn took on a character and appearance by which it could be distin- 
guished. His neighbors then began using this improved corn for 
seed. The fame of several varieties spread until they are well 
known throughout the nation. This does not apply to some so-called 
varieties which have been originated largely through the liberal use 
of printers' ink. In this connection it might be well to state that im- 
proved methods of culture have often accompanied the use of im- 
proved seed corn. 

There is a strong similarity in the histories of the improved breeds 
of plants and animals. In due time corn shows were started, which 
brought out the score-card method of judging corn. One should 
never lose sight of the fact that the establishing of improved strains 
of corn preceded the corn shows and score cards. The latter merely 
emphasized the important characters in which the improved varieties 
of corn seemed to be superior to the common corns grown by the ma- 
jority of farmers. A few farmers and experimenters began to test 
the score-card method of selecting seed corn. The blue ribbon corn 
from the shows did not always outyield the less distinguished corn at 
home. Then one character after another which the score card em- 
phasized failed in carefully conducted tests to produce more than its 
opposing character. Tapering ears slightly outyielded cylindrical 
ears. There was little difference between filled tips and bare tips, 
smooth grains and rough grains, ears shelling a low percentage of 
grain and ears shelling a high percentage. Cunningham (6)^ decided 
that " certain ear characters have been given more consideration than 
their worth as related to yield warrants, while other characters have 
been emphasized that may actually tend to decrease the yields." Love 
and Wentz (9), after reviewing the work of previous experiments 
and conducting extensive experiments of their own, concluded that 
"The judge at a corn show or a farmer in selecting his seed corn can 
not pick the high-yielding seed ears when judging from outward 
characters of the ears. It is evident that the points emphasized on a 
score card are of no value for seed ear purposes and are entirely for 
show purposes." If these conclusions are correct, the work of Reid, 
Riley, Teaming, and scores of other corn breeders has been greatly 

2 Figures in parentheses refer to " Literature cited," p. 113. 



carrier: results in corn experiments. 109 

overestimated and the farmers who have purchased seed of these im- 
proved strains thinking they were getting something better than ordi- 
nary corn have been misled. Very few of the originators of improved 
varieties of seed corn ever practiced " the ear-to-row " progeny test 
which Love and Wentz say is " the only basis left for selecting high- 
yielding seed corn." 

While the winning corn at the shows may not have always out- 
yielded less perfect ears when used for seed purposes, it is an obvious 
fact that the highest yielding varieties of the corn belt, credited as 
such by public approval as well as by varietal tests, produce the largest 
percentage of high scoring ears. Hutcheson and Wolfe (8) have re- 
cently presented experimental data which confirm this observation. 
Do the results with corn in this respect differ materially from the 
experience of animal breeders with livestock shows and score cards ? 

A serious mistake which some agronomists have made has been in 
trying to establish one standard type of corn for the whole country, 
based on the improved varieties of the corn belt. The National Corn 
Show was a failure largely because of this error. Those who attended 
these shows will recall that the northern flints and the southern pro- 
lific varieties did not stand any more chance in the national compe- 
titions that a Jersey steer would at the International Livestock Show. 
And this in face of the fact that given rich river bottom land in the 
South the prolific strains will outyield the single-eared varieties of 
the corn belt by 50 or more bushels per acre. The corn shows and 
score cards when rightly used are potent influences for the improve- 
ment of corn, but they should be based on the well-established types 
of corn prevailing in the locality which they serve. 

EXPERIMENTAL DATA UNSATISFACTORY. 

A great many experiments with corn have been conducted and the 
published results are voluminous. It is very disappointing, however, 
to try to summarize these data, especially if the results are given in 
terms of yield of grain. The summary often presents a quantity not 
sufficiently positive or negative to prove anything. 

CORN BREEDING METHODS. 

The work of improving corn received a great impetus by the publi- 
cation, some twenty years ago, of the results obtained at the Illinois 
Agricultural Experiment Station in increasing and decreasing the oil 
and protein contents of corn by systematic breeding. If such changes 
could be brought about in a few years there seemed to be no limit to 



no JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

what might be accomphshed by selection. Many corn-breeding 
methods came in vogue. The popularity of a method depended 
largely on the personality of its sponsor and the aggressiveness with 
which he kept his views before the public. Some very elaborate 
schemes were proposed for keeping records of the progeny of a selec- 
tion. Just how much has been accomplished by these various methods 
is difficult to say. A number of varieties presumably improved by 
systematic selection have been put on the market ; some of these have 
been very popular. The propaganda work with corn taken in a broad 
sense has been of great benefit. Farmers use better varieties, take 
better care of their seed corn, and practice better methods of culture 
because of it. 

Some of the earliest experiment station work with corn attempted 
to decide the question whether the effects of crossing different colored 
corns was distinguishable in the grain formed from the cross. Some 
botanists felt certain there could be no such immediate effect. Ex- 
periments which proved the contrary were explained on the basis of 
reversion or that the seed must have been impure. Farmers from 
many observations knew there was an immediate effect plainly notice- 
able in certain cases. This debatable question was settled to the sat- 
isfaction of the scientists by the work of De Vries and Correns, which 
was elaborated on by Webber (lo) in this country. The explanation 
was that corn possessed the true xenia characteristic. 

Agronomists were quick to accept this scientific explanation of an 
obvious fact, but they have been unreasonably slow in accepting its 
practical application, which is, that the pollen which fertilizes the silk 
may influence the size and weight of the grain produced as well as 
its color. We still find agronomists conducting variety and ear-to- 
row tests where no provision is made for preventing cross-pollination. 

THE INFLUENCE OF POLLEN ON SIZE AND YIELD OF GRAIN. 

It is the purpose of this paper to show that the common methods of 
variety and ear-to-row testing of corn are unreliable in that there is 
overlooked this factor which may influence the results as much or 
more than the inherent differences in the corns under test. It seems 
to have been quite clearly shown that when two strains of corn are 
crossed there is an immediate elfect on the yield of grain the same 
season the cross is made. 

Some data which indicated such an eifect were presented to the 
American Society of Agronomy at its annual meeting on November 
14, 1910 (i). These data were not published at the time as they were 



carrier: results in corn experiments. 



Ill 



thought to be too meager to justify drawing conclusions from them. 
They were given in the hope that some other agronomists might con- 
firm them or prove them erroneous. Four strains of Boone County 
White corn from widely separated sources had been grown side by 
side, but cross-pollination had been partially prevented by means of 
muslin screens. The 2-year average yields of these strains are 17.3, 
21.6, 18.3, and 26.3 bushels of shelled corn per acre. A mixture of 
equal parts of seed of all four strains gave a yield of 32.4 bushels. 
Four strains of Leaming similarly grown yielded 27.4, 25.3, 24.4, and 
26.9 bushels per acre, while the plat from the mixed seed gave a yield 
of 40.4 bushels. These data, with the results of some subsequent 
experiments which confirmed them were published in 1913 (2). 

Collins (3) had previously noted that when a variety of small- 
grained corn from China with which he was experimenting was polli- 
nated from a large-grained American corn, the hybrid seed " were in 
nearly every case distinctly larger than those showing pure Chinese 
characteristics." Collins and Kempton (5) afterwards found that 
when they mixed the pollen from two varieties of corn and applied it 
to the silks of one of the varieties that the hybrid seed was from 3 
to 2 1 percent heavier than the pure seed grown on the same ear. 

Webber (10) as early as 1900 gave illustrations showing differences 
in form of grains and his notes showed great dififerences in chemical 
composition as well as color due to xenia. He did not mention, how- 
ever, that these differences might affect the yield. 

Wolfe (11) made 37 crosses and found that in 27 of them there 
was an increase in weight of grains, ranging from 0.2 to 16.04 percent, 
while in 10 of the crosses there was a decrease in weight varying from 
0.3 to 13.45 percent. 

It can be readily seen that a factor which influences the yield to 
the extent which these experiments show is exerted by the pollen in 
the immediate grain progeny can not but render of doubt-ful value any 
variety testing of corn which is open to cross-pollination. Likewise, 
any experiments such as testing the correlations of ear characters and 
yield would be subject to this same variable influence, unless the 
parentage was identical for the different ears under test and also for 
the plants furnishing the pollen. 

It has been shown in the experiments cited that the more closely a 
corn is inbred the greater is the effect of the foreign pollen. The 
speaker has often observed much larger yields of corn in his varietal 
tests than would likely be obtained from the varieties grown alone 
under field conditions. It might be noted also that the so-called pure 
strains or improved varieties usually yield highest in varietal tests. 



112 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Of course, there is no such thing as a pure variety of corn. Even 
with the careful selection for many years there has not been developed 
a variety which does not show a mixture of several strains. A pure 
strain is probably neither possible nor desirable. Inbreeding of corn 
has always resulted in decreased yields. • This does not mean that it 
is not possible to establish desirable characteristics for special pur- 
poses such as soft corn for feeding, hard flinty corn for meal making, 
early maturing varieties, and late maturing varieties. Varieties pos- 
sessing these characteristics and many more besides have been origi- 
noted. Crossing is essential and as Hayes (7) has recently shown is 
almost universal under normal field conditions. It would seem to be 
the part of wisdom for corn breeders not to strive for a pure strain, 
but to keep up a mixture of strains having the characteristics desired. 
It is better to work with nature than against her. The market stand- 
ards for corn need not be disregarded or changed at all by this prac- 
tice. This immediate effect of pollen influence on the yield of the 
grain of corn has great possibilities from its practical application. 

It does not appear opportune to disregard the work of the corn im- 
provers of the past, even if they did select their seed from the appear- 
ance of the ears rather than by ear-to-row tests. The evidence in the 
case seems to be that the combined judgment of thousands of farmers 
and seed-corn growers is that there are ear characteristics which are 
correlated with high yields. On the other hand, a few carefully con- 
ducted experiments indicate there is no such correlation. As pre- 
viously pointed out a factor of unknown value is involved in all these 
tests which might increase or decrease the yield. It is not surprising 
that the results of so many corn experiments are of an unsatisfactory 
neutral character. It would seem to be best to advise farmers to con- 
tinue to select seed corn after the well established types of their local- 
ity and then occasionally to introduce some seed from an outside 
source. The more rigidly the variety has been kept from contamina- 
tion the better it is for this crossing. In making the cross the writer 
believes it is better to use seed of the same variety which the farmer 
customarily grows, but not closely related to his own strain, rather 
than take a chance on the results by crossing two distinct varieties. 
The outcross should be at least of the same general type and color as 
the corn which the farmer grows. It is a fairly easy matter to get 
unrelated strains of any of the well-known varieties of corn. There 
is abundant proof of a marked increase in yield of the generation 
from hybrid seed of two closely inbred strains of corn (4), so the 
farmer could expect an increased yield for at least two crops from the 



carrier: results in corn . experiments. 



113 



cross. No technical skill would be required to mix the seed at plant- 
ing time. 

Corn still offers great opportunities to the agronomist who will 
break away from the old methods of conducting experiments and 
work in the light of all the known facts regarding this crop. A 
method must be followed which will allow the plants to develop nor- 
mally and at the same time effectually control the matter of pollina- 
tion. The equipment for such experiments will be expensive, but 
relatively no more so than that used in lysimeter and some other work. 
The importance of the corn crop would seem to justify any such out- 
lay of public funds. 

Literature Cited. 

1. Carrier, Lyman. Preventing cross-pollination of corn by means of muslin 

screens. Unpublished paper read before the third annual meeting of the 
American Society of Agronomy, November 14, 1910. 

2. . The immediate effect on yield of crossing strains of corn. Va. Agr. 

Expt. Sta. Bui. 202. 1913. 

3. CoLUNS, G. N. A new type of Indian corn from China. U. S. Dept. Agr., 

Bur. Plant Indus. Bui. 161. 1909. 

4. . Increased yields of corn from hybrid seed. In U. S. Dept. Agr. 

Yearbook, p. 319-328. 1910. 

5. , and Kempton, J. H. Effects of cross-pollination on the size of seed 

in maize. U. S. Dept. Agr., Bur. Plant Indus. Cir. 124. 1913. 

6. Cunningham, C. C. The relation of ear characters of corn to yield. In 

Jour. Amer. Soc. Agron., 8, no. 3, p. 188-196. 1916. 

7. Hayes, H. K. Normal self-fertilization in corn. In Jour. Amer. Soc. Agron., 

10, no. 3, p. 123-126. 1918. 

8. Hutcheson, T. B., and Wolfe, T. K. Relation between yield and ear char- 

acters in corn. In Jour. Amer. Soc. Agron., 10, no. 6, p. 250-255. 1918. 

9. Love, H. H., and Wentz, J. B. Correlations between ear characters and 

yield in corn. In Jour. Amer. Soc. Agron., 9, no. 7, p. 315-322. 1917. 

10. Webber, Herbert J. Xenia or the immediate effect of pollen in maize. 

U. S. Dept. Agr., Div. Veg. Phys. and Path. Bui. 22. 1900. 

11. Wolfe, T. K. Further evidence of the immediate effect of crossing varie- 

ties of corn on the size of seed produced. In Jour. Amer. Soc. Agron., 7, 
no. 6, p. 265-272. 191 5. 



114 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



THE EFFECT OF THE ENVIRONMENT ON THE LOSS OF 
WEIGHT AND GERMINATION OF SEED POTATOES 
DURING STORAGE.^ 

O. Butler. 

Potatoes generally lose from lo to i6 percent of their weight during 
storage and germinate long before they can be planted, thereby neces- 
sitating " sprouting," an operation which lowers the quality of the 
tubers for seed. Under what conditions can loss of weight be re- 
duced and germination retarded to the desired degree? A study of 
the factors constituting the environment of stored tubers will give 
us the information necessary for the practical solution of the prob- 
lem. These factors are temperature, oxygen supply, and humidity 
of the air. 

TEMPERATURE. 

The temperature at which potatoes are stored has a very marked 
effect on the rate of loss of weight, as is shown by the data presented 
in Table i. 



Table i. — Effect of temperature on the loss of weight of potatoes. 



Mean tem- 


Loss of weight after — 


perature 
















of storage. 


30 days. 


60 days. 


90 days. 


120 days. 


150 days. 


180 days. 


210 days. 


°c. 


Percent. 


Percent. 


Percent. 


Percent. 


Percent. 


Percent. 


Percent. 


3-74 


0.58 


1-43 


1-43 


2.29 


2.88 


2.15 


2.44 


8.82 


1.26 


2.53 


3-37 


4.21 


7.18 






15-75 


1-52 


2.77 


4.01 


6.65 


11.56 







A consideration of the data in Table i shows that, while at the 
mean temperature of 8.82° C. the loss of weight of stored potatoes 
becomes increasingly rapid with age, at 3.74° C. the loss practically 
ceases after the hundred and twentieth day. This effect of low 
temperature is not unusual and I gather from experiments made in a 
cold-storage warehouse that, between o and 4° C. at least, loss of 
weight will fluctuate around a mean value. The reason for this pecu- 
liar behavior is of course apparent when one takes into considera- 
tion the fact that starch in potatoes suffers an increasingly rapid 

1 Contribution from the New Hampshire Agricultural Experiment Station, 
Durham, N. H. Received for publication December 28, 1918. 



BUTLER : STORAGE OF SEED POTATOES. 



hydrolysis as the temperature falls below 8° C.,- thereby causing the 
loss of weight due to transpiration and respiration to become more or 
less perfectly balanced by the gain in weight due to sugar accumula- 
tion. It is therefore clear that from the point of view of loss of 
weight storage at low temperature is highly desirable. But is any 
advantage to be derived from storing potatoes at a mean temperature 
lower than 3.74° C. ? It seems to me that no material advantage 
would accrue, since germination is sufficiently delayed for all prac- 
tical purposes (210 days) when the tubers are stored at this tem- 
perature. 

OXYGEN SUPPLY. 

In the potato the loss of weight on keeping is in part due to respira- 
tion. Hence, a reduction in the available oxygen supply will lower 
respiratory activity and retard metabolic changes. It is of course evi- 
dent that potatoes would decompose in the absence of all oxygen, 
and that asphyxiation would result were the oxygen reduced beyond 
a certain minimum variable with the temperature.^ Potatoes will keep 
in excellent condition in silo provided the temperature does not fall 
too low and Schribaux* has pointed out that tubers stored in a cellar 
and covered with a layer of soil sufficiently deep will keep in a perfect 
state of preservation until August, while if they are covered to a lesser 
depth they will grow and produce a crop of young tubers of excellent 
quality, or if only lightly covered germinate in the usual way. 

In order to test the effect of reducing the oxygen supply on loss of 
weight and retardation of germination an experiment was set up in 
the following manner, using three tubulated bell-jars of the usual 
pattern as recipients for the potatoes. In bell-jar No. i the tubulures 
were plugged with cotton, thus allowing a free diffusion of gases ; 
bell-jar Xo. 2 was connected with a water siphon and 8 percent of the 
contained air was renewed daily; bell-jar No. 3 was also connected 
with a water siphon, but only 0.8 percent of the air was renewed every 
24 hours. The temperature during the course of the experiment 
ranged between 8° and 10° C. 

A few days after the experiment was set up the air in all three bell- 
jars became saturated with water vapor and eventually the potatoes 

2 Muller-Thurgau, H. Uber Zuckeranhaufung in Pflanzen-Theilen in Folge 
nieder Temperatur. In Landw. Jahrb., 11 : 757-818. 1882. 

3 In this connection the reader may consult Stewart, F. C, and Mix, A. J., 
Blackheart and the aeration of potatoes in storage, N. Y. State Agr. Expt. Sta. 
Bui. 436, 321-362. 1917. 

* Schribaux, E. Apropos d'une methods de conservation des pommes de 
terre. In Jour. Agr. Prat., n.s., vol. 7. 1914. 



Il6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

molded. At the end of 90 days, when the experiment was discon- 
tinued, the air in all the bell- jars was very musty, but the potatoes 
were all sound and pure. The potatoes in bell- jar No. i had germi- 
nated, the sprouts being short and stout and having formed roots 
from I to 2 inches long, rather freely covered witji root hairs. In 
bell-jar No. 2 germination was just beginning, but in bell- jar No. 3 
there were no signs of growth. The loss of weight of the potatoes 
during the course of the experiment was as follows : 

Method of treatment. Loss of weight after 90 days- 
Free diffusion of air 1.55 percent 

8 percent of volume of air renewed daily 0.72 percent 

0.8 percent of volume of air renewed daily 0.58 percent 

The data presented clearly show that loss of weight can be ma- 
terially curtailed by reducing the oxygen supply and that asphyxia- 
tion does not occur at 8 to 10° C. even when as little as 0.8 percent 
of the volume of air is renewed daily during 90 days. 

In an experiment on the effect of reducing the oxygen supply on the 
keeping quality of potatoes in which the environment was dry air at 
9.31° C. instead of air saturated with water vapor, the results shown 
in Table 2 were obtained. 



Table 2. — Effect of reduced oxygen and dry air on the loss of weight of 
potatoes during storage. 



Method of treatment. 


Loss of weight after — 


Germination, 


30 days. 


90 days. 


150 days. 


207 days. 


In air 


Percent. 
1.79 
3-37 


Percent. 
4-77 
6.15 


Percent. 
9.21 
9.42 


Percent. 
13-52 
15.16 


None 

After 99 days 



The potatoes in reduce^ oxygen were placed in a rectangular 
galvalized vessel capable of holding about 85 pounds of potatoes. On 
the bottom of the vessel calcium chloride was spread. Next a wire 
false bottom was set in and the vessel fillled with potatoes to about 
2 inches from the cover. The remaining space was occupied by a 
loosely fitting tray containing calcium chloride. The air was intro- 
duced on one side of the vessel below the false bottom and with- 
drawn from the opposite side of the cover. One percent of the 
air was renewed daily by means of a water siphon. 

The data in Table 2 show that germination can be prevented 
more effectively by reducing the oxygen supply than by lowering the 
temperature, as no signs of germination in reduced oxygen at a mean 



BUTLER : STORAGE OF SEED POTATOES. 



temperature of 9.31° C. occurred in 207 days, while at a mean temper- 
ature of 3.74° C. germination had already begun in 210 days. The 
loss of weight of potatoes stored in reduced oxygen and dry air is, 
however, higher than desirable. The air surrounding the tubers 
should evidently not be too thoroly dried if loss of weight is to be 
reduced to a parity to that occurring when tubers are stored at 3.74° 
C. The experiments just detailed was therefore repeated, using 
calcium chloride only on the tray at the top of the container. Under 
these conditions the results obtained were entirely favorable, as the 
following figures show^ The mean temperature during storage was 
9-39° C. 

Loss of weight Loss of weight 

Method of treatment. after 90 days. after 120 days. 

Potatoes in air 8.96 percent. 17.24 percent. 

Potatoes in reduced oxygen... 1.35 percent. 2.79 percent. 

The potatoes in reduced oxygen when the experiment was brought 
to a close on ^lay 25 were in perfect condition and had not germinated^ 
while those in air had long sprouts and were shriveled and flabby. 

HUMIDITY. 

Potatoes lose weight less rapidly, other things being equal, in moist 
than in dry air. In air saturated with water vapor potatoes will 
keep a certain length of time but finally mold and soften, while if the 
air in which they are stored is very dry they lose water rapidly and 
become flabby. The eflPect of dryness of the air, all other conditions 
being equal, on the loss of weight of potatoes is strikingly shown by 
a comparison of the figures just presented with those given in Table 
2. Casting the absolute values into relative numbers and considering 
the temperature of storage as having been the same in both experi- 
ments (it was actually 9.31 and 9.39° C, respectively), we obtain the 
results show^n in Table 3. 



Table 3. — Effect of dryness of the air on the loss of weight of potatoes. 





Relative loss of weight after — 


Method of treatment. 








90 days. 


120 days. 


Stored in air 


100.00 


100.00 


Stored in dry air 


77.56 


89.74 


Stored in reduced oxygen, air partially dried 


15.06 


16.18 



It is perfectly clear that loss of weight of potatoes during storage 
is very markedly affected by the relative humidity of the air. In fact, 
relative humidity is an even more potent factor in reducing loss of 



Il8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



weight during storage than temperature, as we find that a reduction 
of temperature from 8.82° C. to 3.74° C. lowers the loss only 1.8 
times, while a change from dry to moderately dry air efTects a saving 
more than 2.7 times greater for a period of storage of the same length, 
i. e., 120 days. 

SUMMARY. 

We have found in the course of our study of the factors constitut- 
ing the environment of stored tubers that : 

Germination can be satisfactorily retarded by lowering the tempera- 
ture to 3.74° C, or by reducing the oxygen supply to an extent which 
is tantamount to storing in '* dead air." 

Germination can be retarded by storing in " dead air " at a mean 
temperature of 9.31° C. more effectively than by storing in free air 
at 3.74° C. 

Loss of weight is markedly affected by the relative humidity of the 
air. Saturated air and dry air are both to be avoided, the former 
because transpiration is inordinately increased and the latter because 
condensation of water vapor occurs, forming a nidus favorable to the 
development of molds. 

RELATION OF VARYING DEGREES OF HEAT TO THE 
VIABILITY OF SEEDS.^ 

James L. Burgess. 

The practical difficulties found in the use of carbon disulfide for 
the destruction of insects and insect eggs in stored seeds have sug- 
gested the idea that heat might, under certain conditions, replace it 
in the control of insect pests. Professor George Dean, of the Kansas 
Agricultural Experiment Station, made a practical test of this idea 
with mill insects.^ In the summary of the results of his experiment 
he says, " No mill insect can withstand, for any length of time, a 
temperature of from 118° to 122°." He found, moreover, "the de- 
struction of insects by means of . heat to be the most practical, effi- 
cient, convenient, and least expensive method." 

1 Contribution from the North Carolina Seed Laboratory, North Carolina 
Department of Agriculture, Raleigh, N. C. Presented at the eleventh annual 
meeting of the American Society of Agronomy, Baltimore, Md., January 6, 
1919. 

2 Dean, George. Further data on heat as a means of controlling mill insects. 
In Jour. Econ. Entom., 6, no. i, p. 40-53. 1913. 



burgess: effect of heat on germination. 



119 



But, while Professor Dean gave us what seems to be a practical 
method for killing insects on a large scale, he does not seem to have 
ascertained the effect his caloric treatment of the insect has on the 
vitality of the seed it infests. While a high temperature, short of 
burning, may not seriously injure the edible qualities of grains, there 
is no question but that great care must be taken to find the critical 
temperature above which the viability of these grains will be lowered. 
With a view, therefore, of ascertaining this critical temperature for 
various seeds the North Carolina Seed Laboratory undertook a series 
of temperature tests, varying both the time and the temperature by 
holding the temperature at, say, 140° for i, 3, and 5 hours, re- 
spectively; and by subjecting the seeds for very short periods to very 
much higher degrees of heat, say, 212° for 30 minutes, 300° for 5 
minutes, etc., decreasing the time and increasing the temperature. 

The experiment was run with corn, wheat, oats, rye, cowpeas, 
so} beans, and garden beans — seeds most liable to insect depredations. 
Our results were in some cases vitiated by accident, thus rendering 
this discussion of more academic than practical interest. 

Of course it is evident that seemingly unavoidable difficulties lie 
in the way of destroying, by heat, those insects that bury themselves 
deeply in the masses of grain ; but weevils and other insect enemies 
of stored seeds generally begin their work in the surface where they 
can be most easily attacked by heat. Moreover, some ingenious brain 
may find it possible to construct a form of hot blast against and 
through which seeds may be forced in such a way that both insects 
and insect eggs can be killed in the operation. 

We were unable to do anything with that part of our plan re- 
quiring the seeds to be subjected to very high temperatures for very 
short periods. So far as carried out the results of the work are 
shown in Table i. In all cases dry heat was used and applied in a 
hot air sterilizer, the temperatures being measured by a Fahrenheit 
thermometer. 

A temperature of from 140 to 158 degrees continued through five 
hours had no appreciable detrimental effect on the viability of garden 
beans. No check test was used. 

Cowpeas were more susceptible to the influence of heat and were 
almost killed by a temperature of 194° continued through a period 
of 5 hours, while a temperature of 140° for i hour did not seem to 
effect the viability to any great extent. No check test was used. 

Soybeans were practically unaffected by a temperature ranging 
from 140° to 194°, running through a period of i, 3, and even 5 
hours. No check was used. 



120 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table i. — Viability (percentage of germination) of field seeds after exposure 
to various temperatures for one to five hours. 



Kind of seed. 



Tempera- 
ture. 


Length of 
exposure. 


Garden 
beans. 


Cowpeas. 


Soybeans. 


Corn. 


Oats. 


Rye. 


Wheat. 




Hours. 


Percent. 


Percent. 


Percent. 


Percent. 


Percent. 


Percent. 


Percent. 








82 


98 




98 






5 


92 


66 


98 








T pC J 


3 
5 


90 


32 


96 




97 




69 






90 




98 


68 








176 1 


3 


92 


78 


100 


32 






60 




5 




24 


90 






100 




I 






ICO 








68 


5 




2 






98 


93 




212 


5 












92 








• 












60 


{ 


3 












78 


55 


248 1 


I 

5 




















Check 








94 


90 


91 


92 



Our tests with field corn were not satisfactory, as we got only two 
tests to which we could attach any importance. These showed that 
176° for I hour reduced the viability to 68 percent and for 3 hours to 
32 percent. The check test showed a germination of 94 percent. 

Our results with oats were also unsatisfactory, but three tests prov- 
ing of any interest. These three tests seemed to show no appre- 
ciable difference in the effect on the seed of a temperature ranging 
from 140° to 194°, running through periods of i to 5 hours. Due 
to what must have been an experimental error, the check test showed 
lower viability than the heat tests. 

In our tests of rye temperatures of 176° to 212° carried through 5 
hours showed practically no detrimental effect on the viability of the 
seeds. A temperature of 230° for 2 hours reduced the viability to 
78 percent, however, and a temperature of 248° for 5 hours killed 
the seed. 

Wheat was seriously affected by high temperatures. The viability 
in this test was reduced to 60 percent by a temperature of 230° carried 
through I hour and to 55 percent by the same temperature carried 
through 3 hours. The germ was killed by a temperature of 248° 
carried through i hour. The check showed a viability of 92 percent. 

It will be noted that the lowest temperature used, 140° F., was 
10° higher than that found by Professor Dean to be sufficient to kill 
insects. This temperature, and very much higher temperatures, 
some as high as 194° F., seemed to show no detrimental effect on the 
viability of soybeans, oats, and rye. It is not known whether these 
temperatures will kill insect eggs. 



winters: community cotton improvement. 



121 



COMMUNITY COTTON IMPROVEMENT IN NORTH CAROLINA.^ 

R. Y. Winters. 

Rural communities that boast of good roads or good schools are 
not uncommon ; but one rarely find's a community that takes pride in 
the quality of seed it produces. On the contrary, it is the custom of 
most communities to secure a large proportion of their seed from 
other localities. This is particularly true of the small cotton growers. 
Very few growers realize the value of home-bred and home-grown 
seed. Some even believe that crops deteriorate when grown in the 
same locality for several years. This delusion and misleading ad- 
vertisements are partly responsible for the lack of uniformity in 
cotton varieties. With each grower of a community changing cotton 
seed every few years one can very well imagine the effect upon uni- 
formity and quality of staple. 

A survey of cotton varieties in a North Carolina community would 
read somewhat as follows : Two growers planting Half-and-half ; 
four, Cook ; ten, King or a variety of similar origin ; and three grow- 
ing Cleveland Big Boll or some other large-boiled variety. Each 
grower swears by his particular variety but is usually not sufficiently 
interested to prevent its mixing with other varieties at the public 
gin. Assuming that these varieties are fairly pure, the community 
would be producing a little to ^-inch cotton, quite a bit of ^- to 
%-inch, a small amount of 15/16- to i-inch, and in some communi- 
ties a little long-staple cotton. Such a group of cottons is sometimes 
found on a single farm. This condition and the mixing of seed at the 
public and private gins render the production of uniform strains of 
cotton almost hopeless. 

Considering our market conditions, the responsibility for lack of 
uniformity cannot be placed entirely on the producer. To the aver- 
age buyer cotton is cotton, to be bought as cheaply as possible. Until 
improved quality and uniformity mean increased price to the grower, 
we cannot expect a general production of better cotton. The work 
of cotton improvement, therefore, requires the attention of the 
market expert as well as that of the breeder. 

1 Contribution from the North Carolina Extension Service, North Carolina 
Agricultural and Mechanical College, West Raleigh, N. C. Received for pub- 
lication January 20, 1919. 



122 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

VALUE OF COMMUNITY ACTION. 

To improve these conditions in North CaroHna, the extension 
service has estabhshed the community cotton improvement work. By 
community cotton improvement is meant the selection of one good 
variety of cotton for a community, and its improvement in the com- 
munity by saving seed from the best plants. Such a scheme should 
improve the yield and quality, lessen the danger of mixing at the 
gin, and render the community more independent of local markets. 

METHODS AND RESULTS. 

Those who have dealt with community work of any sort no doubt 
realize that the greatest problem lies in the securing of community 
action or cooperation. In this connection, some of the methods used 
and results obtained in our community cotton improvement work may 
be of interest. 

Previous to the fall of 1914, our cooperative cotton improvement 
work was conducted with individual growers. The work with indi- 
viduals was slow and often unsatisfactory. During the summer of 
1914, the matter of community cotton improvement work was dis- 
cussed before the State meeting of farm demonstrators with the hope 
of securing their cooperation, and that winter one community made 
application for the work. Since that time sixteen communities in 
eleven counties have taken it up. 

Each year the county agents are instructed regarding the purpose 
and methods of community cotton improvement. The matter of 
interesting and organizing the community is left to them. When the 
growers of a community become sufficiently interested, application is 
made to the extension service for cooperation. Upon the approval 
of the application a meeting is arranged by the county agent. A 
representative of the experiment station meets with the growers to 
discuss the advantage of growing one good variety in the community, 
and suggests that this variety be chosen by conducting a varietal test 
which will include five varieties grown in the community and five 
recommended by the station. This is discussed and voted on by the 
growers present. If the cooperation is continued and the growers 
agree to choose and improve one variety of cotton in the community, 
the extension service agrees to help in making the varietal test and 
in improving the variety chosen. A census is taken of the varieties 
most generally grown in the community and five are selected for the 
test by the growers present. The station recommends varieties which 
have yielded best under similar soil and climatic conditions. 



winters: community cotton improvement. 



123 



On account of the increasing demand and better price paid for the 
I- to i^^o-hich cotton, special efforts are being- made to introduce varie- 
ties which will furnish a uniform staple of this length. From a list 
of plots oft'ered one or more are selected for making the test. * Care 
is used to select a uniform piece of ground which represents the pre- 
vailing soil type of the community. Other conditions being equal, 
the test plot is located on a public road or on a part of the farm 
easily reached by growers of the community. The variety test is 
planted and harvested under the supervision of the county agent and 
a representative of the station. 

When the test has been planted a circular letter, explaining the test 
and its object, is sent to the cotton growers of the community Dur- 
ing the growing season the test is visited several times by the county 
agent and at least once by a member of the station staff. In the fall 
when the yields have been secured, the results are given in a simple 
report which is mailed to the growers of the community in the form 
of a circular or circular letter. During the winter a meeting is held 
to decide upon the variety to be improved. The variety is selected 
by a vote of the growers. After the selection is made, the growers 
are furnished with the best source of seed for the variety chosen. 
In the spring a few growers plant their entire crop in the new variety 
and others plant enough to get their next year's seed. Growers -of 
the community who wish to further improve the variety are given 
instructions in field selecting and plant-to-row breeding. The actual 
field selection and plant-to-row plantings are followed until a uniform 
strain is established and one or more growers of the community have 
been taught the plant-to-row method of selecting. This usually takes 
three years. 

During the past three years the extension service has helped to 
introduce a good strain of cotton into sixteen communities of eleven 
counties. In the varietal tests the new strains have yielded an in- 
come of $10 to $60 per acre more than the varieties previously grown 
in the communities. Table i contains the results obtained in a com- 
munity of Halifax County and is a fair example of similar tests in 
other communities. 

This community in Halifax County was called to our attention by 
the Division of Markets in 191 5. As a result of its cotton-grading 
work this community was found to produce a very poor quality of 
cotton. Among 949 bales of cotton sampled, 209, or 22 percent, 
stapled less than seven-eighths of an inch in length. Compared with 
other communities of the State this community ranked low in grade 



124 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table i. — Results obtained in a community cotton varietal test in Halifax 

County, N. C, in 1916. 





Yield in pounds 


per acre. 


Per- 


Length 


Value of 


Tot3.1 v&luc 


Variety, 


Seed 


Lint. 


Seed. 


centage 
of lint. 


^ of staple, 
inches. 


lint per 
pound, 
cents. 


of lint and 
seed per 
acre.a 


Cleveland 


1,960 


784.0 


1, 176.0 


dO.O 


H- 

1 6 


20 


Siq7.q6 


Cleveland 


1,510 


566.2 


943-8 


37.5 


7 T 


20 


146.27 


Mexican . . 


1,270 


457-2 


812.8 


36.0 




23 


133.60 


Ricks 


1,400 


490.0 


910.0 


35-0 


1 


20 


129.85 


Med ford 


1,300 


494.0 


806.0 


38.0 


7 
8 


20 


127.01 


Cook 


1,290 


490.2 


800.0 


38.0 


i 


20 


126.04 


Trice 


1,420 


468.6 


951-4 


33-0 


1 

8 


20 


127.02 


Simpkins 


1,170 


432.9 


7371 


37-0 


8 


20 


112.38 


Hawkins 


I, I go 


422.5 


767-5 


35-5 


1 5 

1 6 


20 


III. 36 


Durango 


880 


325.6 


554-4 


37-0 


li 


27 


107.31 



" Estimates based on middling cotton at 20 cents per pound and cottonseed 
at $70.00 per ton, the prices quoted December 7, 1916. 



and length of staple produced. When a survey was made of the 
varieties grown in the community it was found that most of its 
cotton came from poor strains of Simpkins, Ricks, Medford, and 
Hawkins. These are all early small-boiled varieties which usually 
yield a short staple of poor quality. Most growers of the com- 
munity were of the opinion that the large-boiled varieties were too 
late for that section, though the varietal test showed that the better 
large-boiled varieties not only matured but produced almost as much 
cotton at the first picking as v\^as produced in two pickings from the 
small-boiled varieties. Last season the growers of this community 
bought 207 bushels of the improved seed, and enough has been saved 
this season to supply the entire community with improved seed. This 
condition has also made it easier to further improve the strain for 
that section. 

In addition to, the cotton improvement work efforts are being made 
to improve the market conditions. The Office of Markets is co- 
operating in this work by grading the community cotton and locating 
markets for special grades of cotton. A register is kept of growers 
who produce well-bred seed, and a special effort is being made to 
create a local demand for all improved seed. When a grower fails 
to select his seed, or allows it to become mixed, his seed is no longer 
recommended. 

In most communities the ginners have given cooperation. In a few 
cases certain ginners have refused to gin cotton other than that chosen 
by the community, while others have set aside special days for 
ginning community cotton. 



AGRONOMIC AFFAIRS. 12 



AGRONOMIC AFFAIRS. 
MEMBERSHIP CHANGES. 

The membership reported in the February issue was 515. Since 
that time 6 new members have been added, 2 have teen reinstated, 
and 8 have resigned, so that the net membership remains at 515. The 
names and addresses of the new and reinstated members, the names 
of those who have resigned, and such changes of address as have 
come to the notice of the editor and secretary follow. 

New Members. 

Anderson, Mr., Russian Dept., R. Martens & Co., 6 Hanover St., New York. 
BussELL, Frank P., 11 1 Delaware Ave., Ithaca, New York. 
Grisdale, F. S., Vermilion, Alberta, Canada. 
Jones, D. F., Agr. Expt, Sta., New Haven, Conn. 
Pendarvts, Chas. E., Media, III. 

Sampson, Homer C, Dept. Botany, O. S. U., Columbus, Ohio. 

Members Reinstated. 

Hanger, W. E., Ohio State University, Columbus, Ohio. 
HoLBERT, J. R., Bloomington, 111. 

Members Resigned. 

Babcock, F. R., Goddard, L. H., Schuer, Henry W., 

Bailey, C. H., Grimes, W. E., Stone, J. L. 

Call, L. E., Nash, C. W., 

Changes of Address, 

Barbee, O. E., 901 Linden Ave., Pullman, Wash. 
Chapman, James E., Raymondville, Texas. 
Cron, a. B., Chillicothe, Texas. 
Deatrick, Eugene P., Mont Alto, Pa. 
Doneghue, R. C, County Agent, Macomb, 111. 
Foersterling, H., Abor Farm, Jamesburg, N. J. 
Frear, D. W., Sacaton, Ariz. 
Furry, R. L., Carrollton, Mo. 

Gordon, Thos. B., 27 Board of Trade Bldg., Louisville, Ky. 

Hendry, Geo. W., University Farm, Davis, Calif. 

Hill, C. E., Experiment Farm, Waterville, Wash. 

Jensen, L. N., Box 1214, Amarillo, Texas. 

Moomaw, Leroy, Experiment Farm, Dickinson, N. Dak. 

Plummer, J. K., 218 New Berne Ave., Raleigh, N. C. 

Reed, E. P., Urbana, Ohio. 

Richards, P. E., Maryland Expt. Sta., College Park, Md. 

Taggart, J. G., Vermilion, Alberta, Canada. 

Van Nuis, C. D., Agr. Expt. Sta., Durham, N. H. 



126 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



REPORT OF THE SECRETARY-TREASURER. 

November, 1917, to March, igiS. 

Note. — The following report was made by Secretary-Treasurer P, V. Cardon 
to the Executive Committee of .the American Society of Agronomy at the time 
of his resignation in March, 1918, when he was succeeded by Lyman Carrier. 
It should have been printed along with the report of Secretary Carrier in the 
December issue of the Journal of the American Society of Agronomy, but 
unfortunately a copy was not available to the editor at that time. With the 
report of Secretary Carrier, it makes a complete record of the Society's finances 
for 1918. Summarizing the two reports, it is shown that the total receipts of 
the Society for the thirteen and one half months covered by them were $1,796.98, 
which, with the balance of $645.97 turned over by former treasurer Roberts, 
makes a total of $2,442.95. The total expenditures during the period were 
$1,877.95, leaving a balance, as shown by the report of Secretary-Treasurer 
Carrier, of $565. — Editor. 

This statement is submitted as a record- of the official actions of the retiring 
Secretary-Treasurer of the American Society of Agronomy from the date of 
his election at the November, 1917, meeting of the Society to March, 1918, the 
time of his resignation. 

During his brief incumbency, the retiring Secretary-Treasurer enjoyed the 
courteous cooperation of all officials and members of the Society and he regrets 
that he was unable personally to meet and extend his acquaintance among all 
the active agronomists who are supporting this organization. He wishes espe- 
cially to thank Messrs. C. W. Warburton and George Roberts for their assist- 
ance in combining the affairs of the old offices of Secretary and Treasurer, and 
to express his appreciation of services rendered by Messrs. Albert F. Stouffer 
and J. M. Alfaro. , 
I. amendment to constitution. 

At the tenth annual meeting of the Society, held in Washington, D. C, No- 
vember 12 and 13, 1917, the retiring Secretary and Treasurer recomm.ended 
that the two offices be merged and this was done by the election of one man 
to both. As previous notice had not been given, it was not possible to amend 
the constitution at the meeting to make that merger legal, but the Executive 
Committee at its meeting on November 14 voted to submit the necessary amend- 
ment to the Society. . 

Accordingly, each member of the Society was asked to mail to the Secretary- 
Treasurer his vote on the following question : 

Shall Article 4 of the Constitution of the American Society of Agronomy be 
amended to read " The officers of the American Society of Agronomy shall be 
a President, a First Vice-President, a Second Vice-President, and a Secretary- 
Treasurer." 

All of the votes received to date, a total of 163, are in the affirmative. 

2. receipts. 

The following is a classified list of funds received by the Secretary-Treasurer. 
The last report of former Treasurer Roberts showed a balance of $656.22, tho 



AGRONOMIC AFFAIRS. 



127 



only $645.97 was received from him by the writer. This apparent discrepancy 
is due to the fact that after making his report Mr. Roberts received $10.00 
covering five membership dues for 1917 at $2.00 each and paid out $20.25, as 
shown by his vouchers number 132 and 133, leaving a balance of $645.97. 

Funds Received by Secretary-Treasurer — November 20, 1917, to March i, 1918. 

Geo. Roberts, balance from former treasurer $645.97 

C. W. Warburton, collections by secretary 44.06 

Membership fees received 813.70 

9 members for 1917 at $2.00 $ 18.00 

I member for 1918 at 1.50 1.50 

4 members for 1918 at 2.00 8.00 

309 members for 1918 at 2.50 772.50 

3 student members for 1918 at $2.00 6.00 

6 local members for 1918 at .50 3.00 

I member for 1919 at $2.50 2.50 

Exchange on checks .20 

Library subscriptions 151.26 

Through agencies $ 49.76 

Direct 101,50 

Sale of Proceedings and Journal 47-45 

Reprints 20.04 

Total receipts $1,722.48 

Less payments by postage stamps 2.45 

Cash receipts $1,720.03 



3. DISBURSEMENTS. 

The following expenditures have been made by the Secretary-Treasurer : 



New Era Printing Co., printing Journal $ 444.23 

Dec. 3, 1916 $355-6i 

Jan. 25, 191 7 88.62 

E. B. Thompson, Dec. 3, 1917, stereoptican and operator 22.50 

Lewis M. Thayer, printing 49-50 

Dec. 8, 1917 $32-50 

Jan. 9, 1918 13.25 

Feb. 7, 1918 3.75 

Maurice Joyce Eng. Co., engravings 44.54 

Jan. 2, 1918 $ 4.50 

Jan. 22, 1918 6.99 

Feb. 7, 1918 6.50 

Feb. 20, 1918 26.55 

Washington Electrotype Co., maps 5.00 

M. O. Chance, P. M., postage stamps 25.00 

Dec. 12, 1917 $20.00 

Jan. 24, 1918 5.00 

C. W. Warburton, editor's expenses 18.10 

C. R. Ball, acting editor's expenses 4.25 

Albert F. Stouffer, typewriting i5-50 



128 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



J. M. Alfaro, typewriting 



8.50 



Feb. 9, 1918 
Feb. 28, 1918 
March i, 1918 



$2.50 
3.50 
2.50 



Total disbursements . 
Cash balance on hand 



637.12 
1,082.91 



$1,720.03 



4. MEMBERSHIP. 



The last report of the Secretary gave the membership of the Society as 652. 
Since that time 32 members have been added, i has been reinstated, i has died, 
15 have resigned, and 31 have been dropped for nonpayment of 1917 dues, 
leaving a net membership of 638. 

The Secretary-Treasurer has been notified of 35 changes of address and of 
20 instances where members have joined the Army or Navy. 



Respectfully submitted, 



P. V. Cardon. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. April, 19 19. No. 4 



CARRYING CAPACITY OF NATIVE RANGE GRASSES IN 
NORTH DAKOTA.^ 

J. H. Shepperd. 

For many years the writer has believed that a large area of land in 
the western half of North Dakota should be kept in native prairie 
sod for pasturing live stock and has held that it will produce vastly 
more return in that way than can be obtained from the same land if 
plowed and cropped. 

The 1908 report of the field operations of the Bureau of Soils of 
the United States Department of Agriculture, covering a survey of the 
portion of North Dakota lying west of the hundredth meridian, con- 
firms this view and in its statement lists 6,645 square miles of land 
which I interpret from their description is adapted only for grazing. 
The land west of the hundredth meridian in North Dakota consti- 
tutes about three-fifths of the area of the State. The rough or graz- 
ing land constitutes about 17 percent of the area, and is equivalent to 
184 townships of land. 

In 191 3 an active campaign on the part of the writer resulted in an 
arrangement for a trial to determine the carrying capacity of a native 
range pasture of wild grasses to be conducted cooperatively by the 
North Dakota Agricultural Experiment Station and the United States 
'Department of Agriculture on the Northern Great Plains Field Sta- 
tion at ^landan, N. Dak. John T. Sarvis and the writer, representing 

1 Contribution from the North Dakota Agricultural Experiment Station, 
Agricultural College, N. Dak., being a report of work conducted cooperatively 
by that station and the United States Department of Agriculture. Presented 
at the eleventh annual meeting of the American Society of Agronomy, Balti- 
more, Md., January 6, 1919. 

129 



130 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

the two cooperating agencies, have been responsible for the plans and 
have carried out the details of the experiment. 

The land used for this trial is Section 16, Range 81, Township 138. 
It is within the Williston loam series of soils and located in what is 
locally called Custer's Flats, 3.5 miles due south of the city of Man- 
dan, N. Dak. The land is on meridian loi just south of the 47th 
degree of north latitude. The elevation is 1,929 feet. The follow- 
ing weather data have been recorded : 

The average precipitation for 40 years, 1875 to 1914, is 17.41 inches. 

Greatest annual precipitation was in 1876, 30.92 inches. 

Lowest annual precipitation was in 1889, 11.03 inches. 

Greatest precipitation in one month was in June, 1914, 10.68 inches. 

Mean seasonal precipitation, April i to July 31, inclusive, 9.91 inches. 

Month of maximum precipitation, June, 3.5 inches. 

Month of minimum precipitation, February, 0.5 inch. 

The coldest temperature recorded was in January, 1916, — 45° F. 

The hottest temperature recorded was in July, 1910, 107° F. 

Average date of last killing frost in spring. May 15. 

Average date of earliest killing frost in fall, September 15. 

Record latest spring frost, June 7. 

Record earliest fall frost, August 23. 

Prevailing wind, north ; usual velocity, 5 to 10 miles per hour. 

This section of land, with the exception of 50 to 60 acres, is nearly 
level and while it differs from most grazing land in that particular 
permits the laying out of more uniform and comparable pastures 
than could otherwise be had. The soil type is fairly typical of a 
large area in western North Dakota. The rough land is set off for 
a reserve pasture and hence does not enter into the trial. 

The section of land used for the trial had been a hay meadow for 
several years previous to 191 5. Some portions of it had been mowed 
in 1 914. Where these cut areas occurred the cattle grazed more 
readily than they did where it had not been mowed, as that operation 
had removed much dead grass. As prairie grass covers go, this pas- 
ture was densely covered with vegetation at the start. 

The object of the trial is to determine the carrying capacity of 
native pastures without regard to their maintenance or improvement. 
When this factor is worked out consideration can be given to differ- 
ent methods and periods of grazing. 

In 191 5, the entire 250 acres set aside for the experiment was 
fenced as one field and pastured on the basis of 5 acres to the steer. 
This was done to study its carrying capacity and to get the land in 
uniform condition. In 1916 the grazing land was divided into four 
pastures, as shown in figure 10. These pastures contain 30, 50, 70, 
and 100 acres respectively. 



shepperd: carrying capacity of range grasses. 131 



liesarve Pasfore 




Fig. 10. Plot of the section used in the grazing experiments at Mandan, N. 
Dak. The corrals and sheds are at the center of the pasture. The straight 
lines within the various areas represent isolation transects. The crosses show 
the location of the mapped quadrats. Soil samples are taken around these 
areas. The dot in the center of the section shows the location of the well. 
The letters S and M in the northeast quarter of the section represent seeding 
and mowing experiments respectively. 

Corrals, board shelter sheds open on the south, scales, and a squeeze 
for branding were arranged at the converging corners of the four 
pastures, and water was provided there for all of the cattle. A 
70-acre rotation pasture was begun in 191 8 and water was provided 
separately in the corner of that field. 

Ten 2-year-old grade beef-bred range steers are the standard graz- 
ing force for each pasture, which makes the pasturing ratio 3, 5, 7, 
and 10 acres of grass area to the 2-year-old steer. 



132 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



By correspondence and questionnaires the estimates of about two 
hundred farmers on the carrying capacities of native and domestic 
pastures for that region of the State were secured. They range 
from 6 to 12 acres of native grasses for a 2-year-old steer. 

One of the first factors to be determined in this trial seemed to be 
that of the unit of measure in pasturing with cattle. The 2-year-old 
beef steer was decided upon as the unit, as (a) he seemed to be the 
unit most used by ranchmen figuring on this question; (b) he has 
about the average capacity for consumption between yearlings, cows, 
and large steers ; and (c) he is not disturbed like the heifer by periods 
of oestrum or by calving during the trial. 

The trial calls for 55 head of 2-year-old steers each year. It has 
been difficult to find suitable animals on the market in the spring, and 
yearling cattle have had to be used in part for two seasons. Conse- 
quently, the comparisons of the consuming and gaining capacity of 
yearling steers and 2-year-olds are features which have been strongly 
forced upon us for consideration. This matter has been disposed of 
by placing approximately a standard weight of cattle per pasture on 
the land and by comparing the total gains in live weight per pasture 
and per acre. The w^eights of the animals when put on the dififerent 
pastures each year are shown in Table i. 

Table i. — Weight and number of cattle per pasture by years. 



Year. 



Pasture. 



Number of 
h.ad. 



Weight of 
cattle per 
pasture. 



Days pas- 
tured. 



Average 
weight pei 
head. 



I915 
I916 



I917 



All as one (250 acres) 

lOO-acre 

70-acre 

50-acre 

30-acre 

Total or average . 

lOO-acre 

70-acre 

50-acre 

30-acre 

Total or average . 

lOO-acre 

70-acre 

50-acre 

30-acre 

Rotation 70-acre 

Total or average . 



53 

14 
12 
12 
12 



Pounds. 
42,745 

8,705 
7,580 
7,310 
7,600 



40 

14 
14 
14 
14 
14 



70 



31-195 

7.735 
7,800 
7,700 
7.730 



30,965 

7,090 
7,070 

6,945 
6,970 
7,020 



109 

149 
149 
149 
149 



155 
155 
155' 
114 



157 
157 
157 
107 
157 



Pounds. 
806.5 

621.8 
631.8 
609.2 
6333 



623.9 

773-5 
780.0 
770.0 
773-0 



774-1 

506.4 
505-0 
496.0 
498.0 
501.4 



35.095 



501.4 



shepperd: carrying capacity of range grasses. 



133 



It will be seen by Table i that 7,000 to 7,500 pounds weight is our 
approximate standard, or a 700- to 750-pound steer is our approved 
unit weight when the cattle are placed in the pasture in the spring. 
In all cases where more than 10 head of steers to the pasture were 
used some yearlings have been included. 

In this discussion thruout I will refer to the cattle on the basis of 
10 head of 2-ycar-old steers per pasture, for convenience in making 
comparisons. In some cases 14 head of yearling cattle have been 
used instead of 10 head of 2-year-olds. 

The reserve pasture has served a very useful purpose in providing 
grass for the lot of cattle given 3 acres per 2-year-old steer after their 
supply of grass was exhausted and also by supplying substitutes when 
a trial animal was disabled. 

Quadrats 20 by 300 feet in area were fenced ofif early in 191 5 in 
the 30-acre pasture, which it was anticipated would be overgrazed, 
and in the lOO-acre pasture, which it was expected would be under- 
grazed during the trial. These were isolated for the purpose of 
making floral population studies. Beginning in 1916, perquadrats 4 
meters square have been opened for grazing each year, and a per- 
quadrat of similar size has been taken in from the body of the pas- 
ture. If a population study can be made each year for ten years as 
planned, at the end of that time data will be secured on areas that 
have been grazed from one to ten years. Quadrats are established at 
the points marked -)- on the pasture diagram, these having been laid 
out by surveying from known points. On these quadrats the grass 
species population is counted and mapped at intervals during the trial. 
About 175 different species of plants were collected by Mr. Sarvis 
during the season of 191 5 and made into a herbarium at the Federal 
station at Mandan for purposes of comparison. A view of a sec- 
tion of the pasture in 1915, when the trial was begun, is shown in 
Plate 3, figure i. 

Following is a list giving the dominant, primary, and secondary 
species in the pastures : 

Dominant species, Boiiteloua gracilis (blue grama) and Stipa comata (west- 
ern needle grass). 

Primary species, Stipa viridula (feather bunchgrass), Andropogon scoparius 
(little bluestem), Andropogon furcatus (big bluestem), Stipa spartea (porcu- 
pine grass), and Koeleria cristata (prairie Junegrass). 

Secondary species, Aristida longiseta (wiregrass), Agropyron smithii (west- 
ern wheatgrass), Calamovilfa longifolia (sandgrass), Agropyron caninum 
(bearded wheatgrass), Bouteloua curtipendula (tall grama), Bulbilis dacty- 
loides (buffalo grass), Poa palustris (false redtop), Agropyron tenerum (slen- 
der wheatgrass), Elymus canadensis (Canadian wild rye), and Sporobolus 
brevifolius (prairie rushgrass). 



134 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

A number of species occur that are not abundant enough to enter 
into consideration as supplying or hindering pasture. 

Blue grama (Boiiteloua gracilis), typical of the short-grass region, 
and western needle grass {Stipa comata) are the predominating spe- 
cies. Needle grass is representative of the long grass or prairie for- 
mation. Apparently the grass land occupants of this pasture would 
in majority belong to this formation. The blue grama and western 
needle grass association on these pastures is dominated by the blue 
grama, which covers approximately twice as much ground surface 
as the needle grass. 

The blue grama from the standpoint of grazing ranks above the 
needle grass. It stands trampling well and responds to light rains 
that would not be sufficient to stimulate growth in most other grasses. 
It is greatly relished by stock. Needle grass furnishes early grazing 
in the spring and regularly to the time when the needles are formed. 
When the needles are on, the stock avoid it for a couple of weeks 
until the needles drop, after which it is again readily eaten for the 
remainder of the season. 

One of the most relished grasses is the big bluestem (Andropogon 
fiircatus). It is not plentiful enough to supply much forage, occur- 
ring mostly in the ravines. It makes abundant growth, stands drouth 
well, and recovers rapidly from grazing. It is always grazed closely 
by the stock and hence has little chance to spread. On these pastures 
this grass was eaten almost exclusively when the stock were first 
turned in until it was closely grazed and the new growth has been 
fed down as fast as it has appeared during the four years of the 
trial. 

Western wheatgrass (Agropyron smithii) is one of the best range 
grasses, but occurs too sparsely in the pastures to be of much conse- 
quence. Three grasses of doubtful value and little relished are little 
bluestem (Andropogon scoparius) , wiregrass (Aristida longiseta), 
and prairie rushgrass {Sporoholus hrcvifolius) . All three furnish 
some acceptable grazing when young, but soon become harsh and 
woody. These three are bunch grasses and form dense tussocks. 
When the 30- and 50-acre pastures grew short the steers left these 
grasses standing, but when hunger pressed them the tufts were grazed 
close to the ground. Bunches of wiregrass left by the cattle are 
shown in Plate 4, figure i. In figure 2 a portion of the 30-acre pas- 
ture is shown in which all grasses are grazed close. Plate 5 shows 
other views of the pastures. 

Plants other than grasses also occur in small percentage and are 



SHEPPERD : CARRYING CAPACITY OF RANGE GRASSES. 



allowed to grow by the grazing steers except when necessity forces 
the cattle to eat them. Their chief importance is that they occupy 
ground which otherwise might furnish grass and there is a possibility 
of their affecting the flavor of the flesh of animals when eaten. 
Most of these plants are eaten to some extent, in the pasture not over- 
stocked, in some stage of their growth. 

Following is a list of the plants other than grasses which occur on 
these pastures. 

Dominant species. 

Carcx filifolia (nigger-wool sedge). It is estimated that this plant covers 

from I to 2 percent of the surface of the ground. 
Carex heliophia (sedge). This plant covers less than i percent, but a larger 

area than any of the following. 

Primary species. 

The following list of primary species is arranged in their order of abundance 
as based upon actual counts made of 100 quadrats. 

Percent. 

Artemisia gnaphaloides (wild sage) 24.0 

Solidago rigida (goldenrod) 17.4 

Artemisia canadensis (wild sage) 12.5 

Psoralea argophylla (silver-leaved psoralea) 12.2 

Artemisia f rigida (wild sage) • 11.6 

Echinacea angustifolia (purple coneflower) 8.7 

Polygala alba (white milkwort) 6.6 

Ratibida columnaris (yellow coneflower) 4.3 

Secondary species. 

Lacinaria punctata, Aster multiflorus, 

Oxytropis lambertii (loco weed), Sideranthus spinulosus, 

Hedomia hispida, Lactuca pulchella, 

Salsola pestifer (Russian thistle), Vicia sparsifoUa, 

Comandria pallida, Malvastrum coccineum, 

Senecio plattensis, Cherrinia aspera, 

Petalostemon purpiireum, Petalostemon candidum. 

The percentages of the vegetation removed by the cattle from the 
various pastures are shown in Table 2. 



Table 2. — Percentage of vegetation grazed from each pasture yearly. 



Year. 


Pasture. 


■ 










loo-acre. 


70-acre. 


50-acre. 


30-acre. 


1916 


30 


50 


70 


95 


1917 


40 


60 


90 


100 


1918 


55 


75 • 


100 


100 



136 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



In the ICQ- and in the 70-acre pastures the grazing is more patchy 
than in the 50- and 30-acre ones and was noticeably so from the year 
1916 forward. 

The pasture ground cover was determined by measurement and 
count and was found to be about 60 percent. In other words, 60 
acres in 100 are covered with vegetation of some kind on these pas- 
tures. The grass cover, however, would be called heavy or dense 
range grass by stockmen. 

Two hundred and thirteen head of cattle have been used in this 
trial during the four years that it has been under way. The fact that 
they have gained an average of 1.86 pounds per head per day during 
the time they have been grazed is evidence that they have been thrifty 
and reasonably well-bred stock. 

I find few data covering the carrying capacity of domestic pastures 
which throw light on gains of cattle or carrying capacity of full- 
season grazing. Morrow of the Illinois station in the early eighties 
(1880, 1882, 1883, and 1885) carried on grazing experiments with 
beef steers. In his experiments, 35 steers pastured for 154 days 
showed an average gain per day of 1.9 pounds. Morrow does not 
describe his pasture nor his steers, but I feel safe in assuming that 
he used grade beef cattle and that he grazed them on the standard 
domestic or tame grass pastures of Illinois. 

Hunt of the Virginia station in the December, 1918, issue of The 
Field reports that he pastured steers in 191 5, 1916, and 1917, pre- 
sumably on bluegrass pasture. He reports that 15 steers averaging 
1,100 pounds pastured for 135 days showed an average gain of 2.04 
pounds per day. Hunt does not give the area of pasture supplied 
per steer. He used Shorthorn and Hereford grades in his trial. 

Carrier and Oakley at the Virginia station in 1909, 1910, and 191 2 
carried on a pasturing trial, in which 30 steers pastured for 151 days 
averaged 2 acres per head and gained an average of 1.52 pounds 
per day. These steers were on a 12-year-old bluegrass pasture. 
Carrier and Oakley do not describe their cattle more than to say that 
2-year-old steers were used in 1909 and yearlings the other two years. 

The Mandan results give an average of 1.86 pounds per head per 
day and make a reasonably good comparison with the Illinois and 
Virginia station gains. They may, I believe, be called standard for 
range-grazed cattle. 

Shorthorn, Angus, and Hereford grade and crossbred cattle have 
been used in the Mandan trial. The majority have been range-bred 
stock, altho a few farm-bred cattle have been used. Except that 



Journal of the American Society of Agronomy. 



Plate 3. 




Fig. 2. Type of cattle used in 1915. 



Journal of the American Society of Agronomy. 



Plate 4 




Fig. I. Close view of the Aristida bunches left by cattle. Note close grazing 
around them. Also compare with Plate 4, figure 2, where scant pasture forced 
the cattle to eat this forage plant. 




Fig. 2. Area in foreground of 3-acre-per-steer pasture is quadrat opened to 
grazing in 1918. Background shows completeness of grazing, or 100 percent. 
Note how closely the 3-acre-per-steer cattle grazed a heavy growth the first 
season it was opened to them. Compare Plate 5, figure i, where a similar area 
was opened to the lo-acre-per-steer lot of cattle. 



Journal of the American Society of Agronomy. 



Plate 5. 




Fig. I. View of area in lo-acre-to-the-steer pasture opened to cattle in the 
spring of 1918. Note how Httle grazed it is compared with Plate 4, figure 2, 
the 3-acre-to-the-steer pasture opened to grazing at the same time. 




Fig. 2. View of area closed in 1917. Note the thickening of the cover on this 
3-acre-to-the-steer pasture with two years' rest period. 



SHEPPERD : CARRYING CAPACITY OF RANGE GRASSES. 



they were wild and hard to handle on that account range stock are 
more satisfactory than domestic cattle. A group of the cattle used 
in 191 5 are shown in Plate 3, figure 2. 

Two-year-old steers have been secured in so far as that has been 
possible, but for two seasons a number of yearlings had to be sub- 
stituted. In 191 8 some heifers were taken. Extra numbers are 
used when younger cattle are substituted so that the live weight 
per pasture has been nearly constant at from 7,000 to 7,500 pounds. 

The five pastures already described have been pastured by groups 
of cattle carefully divided into bunches so as to be uniform in type, 
age, weight, and general character at the beginning of the grazing 
season. Approximately the same live weight has been placed in each 
pasture lot at the opening of the pasturing season each year. Begin- 
ning with 191 6 and from that season on four pastures have been 
stocked with the same number and approximate weight of cattle or 
at the rate of 3, 5, 7, and 10 acres to the 2-year-old steer. At the 
close of the second year (1917) of separate pasture grazing the 
3-acre-to-the-steer pasture was exhausted as shown by a shrinkage 
in weight of the cattle. 



Table 3. — Results of grazing experiments with steers in 1918 at Mandan {2 
two-year-olds and 12 yearlings in each pasture). 

30-ACRE PASTURE. 



Date ot 
weighing. 


Length 
of period. 


Total 
.weight. 


Average 
weight. 


Gain or loss 
per lot. 


Average 
gain or loss 
per head. 


Gain 
per acre. 


Average 
gain or loss 
per day. 


May 17 

May 31 

June 30 

July 30 

Aug. 29° 


Days. 

15 
30 
30 
30 


Pounds. 
6,970 
7,390 
8.855 
9.050 
9.150 


Pounds. 
498 
528 

633 
646 

654 


Pounds. 

420 
1,465 
195 
100 


Pounds. 

30.0 
104.7 
14.0 
7-1 


Pounds. 


Pounds. 

2.0 

3-5 
0.5 
0.2 


Total 


105 




2,180 


155-8 


72.7 


1-5 


50-ACRE PASTURE. 


May 17 

May 31 

June 30 

July 30 

Aug. 29 

Sept. 28 
Oct. 20 


15 
30 
30 
30 
30 
22 


6,945 
7,715 
9,020 
9.760 
10,280 
10.970 
10,715 


406 
551 
644 
697 
734 
784 
765 


770 
1,305 
740 
520 
690 
-255 


55-0 
93-2 
52.9 
37-1 
49-3 
— 18.2 




3-7 
3-1 
1.8 
1.2 
1.6 
- -9 


Total 


.57 




3.770 


269.3 


75-4 


1.8 



138 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table 3. — Results of gradng experiments. — Continued. 



70-ACRE PASTURE. 



May 17 

Mav 31 

June 30 

July 30 

Aug. 29 

Sept. 28 
Oct. 20 


15 
30 
30 
30 
30 
22 


7,070 
7>905 
9,380^ 
10,035 
10,500 
11,190 
11.370 


505 
565 
670 
717 
750 
799 
812 


835 
1,475 
805 

465 
690 
180 


59-7 
105.4 

57-5 
33-2 
49.3 
12.9 




4.0 

3-5 
1.9 
I.I 
1.6 

0.6 


Total 


157 






4,450 


318.0 


63.6 


2.0 


1 00- ACRE PASTURE. 


May 17 

May 31 

June 30 

July 30 

Aug. 29 

Sept. 28 
Oct. 20 


15 
30 
30 
30 
30 
22 


7.090 

7.645 
8,580 
9,620 
10,490 
11.255 
11,390 


506 
546 
613 
687 
749 
804 
814 


555 
935 
1,040 
870 
765 
135 


39-6 
66.8 

74-3 
62.1 
54.6 
9-7 




2.2 
2.4 

2.5 
2.1 

1,8 


Total 


157 






4.300 


307.1 


43-0 


1.9 


ROTATION PASTURE. 


Date of 
weighing. 


Length 
of period. 


Total 
weight. 


Average 
weight. 


Gain or loss 
per lot. 


Average 
gain or loss 
per head. 


Gain 
per acre. 


Average 
gain or loss 
per day. 


May 17 

Mav 31 

June 30 

July 30 

Aug. 29 

Sept. 28 
Oct. 20 


Days. 

15 
30 
30 
30 
30 
22 


Pounds. 
7,020 
7,800 
8,885 
9,375 
10,120 
10,690 
10,710 


Pounds. 
501 
557 
635 
670 

723 
764 
765 


Pounds. 

780 
1,085 
490 
745 
570 
20 


Pounds. 

55-7 
77-5 
350 
53-2 
40.7 
1.4 


Pounds. 


Pounds. 

3-7 
2.6 
1.2 
1-7 
1.4 
.1 


Total 


157 






3.690 


263.6 


52.7 


1-7 



^' Cattle removed from pasture. This lot of cattle showed a loss in weight 
of 240 pounds during the last ten days of August, or at the rate of 1.7 pounds 
per head per day. 

^ Weight after substitution, 9,230 pounds. 



In the third year the 3-acre-to-the-steer pasture was exhausted 
August 30, or at the end of 106 days, and the cattle lost weight regu- 
larly after that time until removed from the pasture. On September 
30, at the end of 137 days, the 5-acres-to-the-steer pasture was ex- 
hausted and the cattle began losing weight rapidly. Seven acres to 
the steer seems to be carrying the cattle satisfactorily. A rotation 
pasture supplying 7 acres to the steer was started in 1918. This pas- 
ture lies adjacent to the original 70-acre pasture and is fenced into 



shepperd: carrvtxc. capacity of range grasses. 



139 



three equal parts consisting of 23V|'{ acres each. The cattle were pas- 
tured on A, B, and C sections of it respectively during the first, mid- 
dle, and latter portions of the grazing season din-ing 191 8. In 1919 
they will be pastured first on B, second on C, and third on A. In 
1920 they will be pastured first on C, second on A, and third on B, 
and continue in a similar repeating rotative manner thruout the trial. 
Table 3 gives the detailed results for the cattle in the third year of 
the trial. 1918. 



Table 4. — Summary of results of gracing experiment at Mandan in igi8 with 
2 izfo-year- olds and 12 head of yearling cattle in each pasture. 



Data. 


Pasture. 


100 acres. 


70 acres. 


50 acres. 


30 acres. 


Rotation, 
70 acres. 


Total weight May 16, pounds. . . 


7.090 


7,070 


6,945 


6,970 


7,020 


Total weight Oct. 20, pounds. . . 


11,390 


11.370 


10,715 


9,150" 


10,710 


Average weight May 16, pounds 


506 


505 


496 


498 


SOI 


Average weight Oct. 20, pounds. 


814 


812 


765 


654" 


765 


Gain per pasture in 158 days, 














4.300 


4.450 


3.770 


2,l80« 


3.690 


Average gain per head, pounds. 


307 


318 


269 


156" 


264 


Average gain per day, pounds. . . 


1.9 


2.0 


1-7 


1.4'^ 


1.7 




43-0 


63.6 


75-4 


72.7 


52.7 



Weight September i when 30-acre pasture was exhausted. 



Table 5, which gives a stmimary of the pasturing results for three 
years, shows similar altho more marked results than those for 191 8 
as the per acre gain from heavy and light pasturing. 

In the summary table for 191 8 it will be seen that the added weight 
or gain per acre of pasture decreases with the acreage of grass sup- 
plied per steer. Three acres to the steer in 1918 gave 72.69 pounds 
of gain per acre or 69 percent more gain per acre than 10 acres to 
the steer, despite the fact that it had been pastiu'ed to exhaustion the 
previous year and lasted only 106 days, while 10 acres to the steer 
was grazed 157 days. The increases per acre of grass land were in 
reverse ratio to the acreage supplied per head. 

Carrier and Oakley report results from trials on an old bluegrass 
pasture as follows : 

3 steers grazed 151 days on 21/2 acres per steer gained 112 pounds per acre. 
6 steers grazed 151 days on acres per steer gained 198 pounds per acre. 

These gains per acre are naturally much heavier than those secured 
under range conditions, but show a similar spread in the total gain 
per acre on heavy and light pasturing. It is interesting to note also 



140 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table 5. — Average gain per head for the entire pasturage period, gain per 
head per day, and gain per head per acre in gradng experiments at 
Mandan in IQ16, 1917, and 1918. 

AVERAGE GAIN PER HEAD. 



Year. 


Number of 
days. 


Pasture. 


loo-acre. 


70-acre. 


50-acre. 


30-acre. 


70-acre rota- 
tion. 


1916 

I917 

1918 


149 
158 


271. 1 
241.5 
307.1 


324-9 
213.0 
318.0 


321.2 
227.0 
269.3 


271.7 

124.0*^ 

155-8^ 


263.6 


Average 


273.2 285.3 


272.5 


183-5 




AVERAGE GAIN PER DAY. 


1916 

I917 

1918 


149 
155 
158 


1.82 
1-37 
1.94 


2.18 
1.46 
2.00 


2.16 
1.46 
1.72 


1.82 
1.08 
1.40 


1.70 


Average 




I.71 


1.88 1.78 


1-43 




GAIN IN WEIGHT OF CATTLE PRODUCED PER ACRE. 


1916 

I917 

I918 


149 
155 
158 


37-97 
24.15 
43-00 


55-71 
30.43 
63-59 


77.10 108.66 
45.40 66.66 
75.40 72.69 


52.71 


Average 




35-04 


49-91 


65.96 82.67 





Pasture exhausted September i after 106 days grazing. 
^ Pasture exhausted September 18 after 123 days grazing. 



that Virginia bluegrass sod improved from heavy grazing while the 
lightly grazed pasture grew weedy. These experimenters report no 
advantage from rotation pasturing. 

The rotation pasture (7 acres to the steer) at Mandan gave only 
five-sixths the gain obtained from the nonrotated 7-acre-to-the-steer 
pasture. Five steers from this pasture broke out and were returned 
after covering 30 miles. They were gaunt and doubtless shrunk con- 
siderably during that time. They were turned in on section C of 
their pasture September i and were out September 11 to 14. The 
grazing was particularly good in division C at that time, but the cattle 
were nervous and restless when returned. This difference seems to 
me, however, to be chiefly chargeable to the fact that the rotation 
70-acre pasture had not been grazed down in several years and con- 
tained much dead grass, which is either not relished, so that the cattle 
do not eat heavily of it, or is not nutritious and fails to give good 



SHEPPERD: CARRVIXG CAI'ACITY OF RANGE GRASSES. 



141 



gains when consumed. The other 7-acre-to-the-steer pasture had 
been grazed regularly for three years and hence was reasonably well 
pastured down. Further evidence that the fresh grass of early 
spring gives nuich more rapid gains than the drier grass of the later 
season is shown bv Table 6. 



Table 6. — Ga{)is made per day by grazing periods, igij to 1918. 



Period. 


Number of 


Inclusive dates. 


Length of 


Gains per day 


steers. 


period, days. 


per head, pounds 


Season 


S3 


July 17 to Nov. 3, 19 15 


109 


1.8 


1st 


SO 


June I to July 17, 1916 


47 


3.4 


2d 


SO 


July 18 to Sept. 13, 1916 


58 


2.1 


3d 


SO 


Sept. 13 to Oct. 13, 1916 


30 


0.8 


4th 


SO 


Oct. 13 to Oct. 27, 1916 


14 


-0.9 




40 


May 26 to June 30, 1917 


35 


3.6 


2d 


40 


July I to Aug. 29, 1917 


60 


1-5 


3d 


40 


Aug. 29 to Sept. 28, 1917 


30 


0.7 




'40 


Sept. 28 to Oct. 29, 1917 


30 


-0.6 


ist 


70 


May 16 to July i, 1918 


46 


3.0 


2d 


70 


July I to Aug. 30, 1918 


61 


1.4 


3d 


56 


Aug. 30 to Sept. 30, 1918 


30 


1.6 


4th 


56 


Sept. 30 to Oct. 20, 1918 


20 




Summary by periods for 3 years, J916-1918. 


I3t 


160 




44 


3-26 


2d 


160 




60 


1.64 


3d 


146 




30 


1.07 


4ih 


146 




22 


- .47 



Summary entire season for 4 years, ig 15-1918. 
212 steers 140 days, average gain per day 1.86 



It will be noted that for the three years the average gain per day 
for the first 44 days is double that of the next 60 days, while the gain 
for the 30 days following the first 104 days of the season is only 1.07 
pounds, or less than one-third that of the first 44 days. During the 
last 22 days of the grazing season in the month of October the cattle 
sustain- a loss of 0.47 pound in weight per day. 

The average gain per day secured in a 3-year trial when grazing 
44. 104, 134, and 140 days respectively is shown below. This is a 
summarized comparison of the total gains which may be expected at 
dift'erent dates in the full season. 



142 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Gain per day , 



Period. pounds. 

First period, i6o steers, 44 days '. 3.26 

First and second periods, 160 steers, 104 days 2.33 

First, second, and third periods, 157 steers, 134 days 2.06 

First, second, third, and fourth periods, 213 steers, 140 days 1.86 



Cattle as thin as stocker steers are in the spring naturally gain more 
rapidly than they do later, but I do not believe that the large and 
consistent gains here shown can be accounted for in that way. 

These results do not bear out the theory that amide substances 
found in succulent plants have less value in producing gains in live 
stock than the protein substance found in more mature plant growth. 

Four years is too short a time to give conclusive results from a 
grazing trial, but the evidence seems reasonably conclusive that less 
than 7 acres to the 2-year-old steer will not carry and that the prin- 
cipal gains are made by cattle during the early part of the season. 
Also, that late season grazing is done without gains or at an actual 
loss in weight. They also indicate that the number of acres supplied 
per steer in practice will depend upon the farm management ques- 
tions of the cost of supplementing pastures and the price of land used 
for grazing, as heavy early season pasturing gives maximum per acre 
yields. 



LEIGHTV .S: IIUTCIIESON : BLOOMING OF WHEAT. 



ON THE BLOOMING AND FERTILIZATION OF WHEAT 
FLOWERS/ 

C. E. Leightv and T. B. Hutciieson. 

The observations and experiments on wheat flowers reported in 
this paper were made at the Minnesota Agricultural Experiment Sta- 
tion, St. Paul, Alinn., and at the Arlington Experiment Farm, Ross- 
lyn, Virginia. Part i deals with the time of blooming of flowers of 
several varieties of wheat. Part 2 deals with the fertilization of 
emasculated wheat flowers that takes place when these are left unpro- 
tected from foreign pollination. 

I. Time of Blooming of Wheat Flowers. 

In the observations made on the time of blooming of wheat flow- 
ers, heads of wheat of several varieties were marked before they had 
begun to bloom and diagrams of these heads were made. Heads in 
the same stage of development were chosen, so far as possible, on 
which it was expected that blooming would soon begin. These heads 
were then examined at least three times a day, usually at 7 a.m., 12 
m., and 5 or 6 p.m., some variation from these hours being noted 
later. At eacli examination any flowers having bloomed since the 
last examination were so recorded on the diagram. A flower was 
considered as having bloomed from the time the glumes had opened 
appreciably. 

The process of blooming of a wheat flower is very rapid. From 
the time that they first begin to open the glumes may be fully open in 
less than i minute ; the anthers may be extruded and emptied of 
pollen within 2 or 3 minutes ; the glumes may be half closed within 5 
minutes, loosely closed within 10 minutes, and tightly closed at the 
end of 15 or 20 minutes. The entire process, from the time that the 
first opening movement of the glumes can be observed until they are 
again tightly closed, seldom requires more than 20 minutes. 

The period from 6 p.m. to 7 a.m. is hereafter referred to as 
" night," altho several hours of daylight are included. It was not 
determined whether the blooming takes place only in these hours of 

1 Joint contribution from the Office of Cereal Investigations, United States 
Department of Agriculture, Washington, D. C. and the Minnesota Agricul- 
tural Experiment Station, University Farm, St. Paul, Minn. Received for 
publication January 24, 1919. 



144 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



light or whether is occurs partially or wholly in darkness. It was 
impracticable under the conditions of experiment both in Minnesota 
and at Arlington Farm to make the data thus complete. 

OBSERVATIONS ON TIME OF BLOOMING AT THE MINNESOTA EXPERIMENT STATION. 

In Tables i, 2, and 3 the results of the observations on time of 
blooming made at the Minnesota Agricultural Experiment Station 
are shown, Table i setting forth those made on the common spring 
wheats. 

Table i. — Numbers of flowers per head and per variety of common spring 
zvhcat blooming between stated hours within stated periods in July, 
191 4, at the Minnesota Agricultural Experiment Station. 



"velvet chaff." 



Head No. 


Flowers blooming between 


Period of blooming. 










6 p. m. and 7 a. m. 


7 a. m. and 12 m. 


12 m. and 6 p. m. 


I 


18 


22 


3 


July 2-4 


2 


29 


21 





July 2-4 


3 


24 


14 


4 


July 1-4 


4 


24 


22 


2 


July 2-4 


5 


20 


10 


5 


July 2-4 


Total . 




89 


14 




haynes bluestem. 


I 


21 


9 


8 


July 6-8 


2 


34 


15 


3 


July 6-8 


3 


28 


9 


5 


July 6-8 


4 


28 


10 


4 


July 6-8 


5 


27 


10 


3 


July 6-8 


Total 


138 


53 


23 




GLYNDON fife. 


I 


23 


9 


5 


July 1-3 


2 


15 


7 


10 


July 2-4 


3 


15 


2 


7 


July 2-4 


4 


15 


6 


4 


July 3-4 


5 


9 





5 


July 3-4 


Total 


77 


24 


31 




Total three va- 












330 


166 


68 





It may be noted in these common spring varieties that a greater 
part of the blooming takes place between 6 p.m. and 7 a.m. The pro- 
portion is 330 at night to 234 in the day. In "Velvet Chaff" and 



LEIGHTY & HUTCHESON : BLOOMING OF WHEAT. 



Bluestem most of the day blooming is in the forenoon, 89 and 53 
flowers respectively of these two varieties blooming in this period, 
while 14 and 23 respectively bloomed in the afternoon. In Glyndon 
Fife there is very little difference between the amount of forenoon 
and afternoon blooming, there being 24 before noon and 31 after 
noon. The night and total day bloomings for the three varieties are : 
"Velvet Chaff," 115 night, 103 day; Haynes Bluestem, 138 night, 
76 day ; Glyndon Fife, 77 night, 56 day. 

In Table 2 'are shown the observations made on two varieties of 
durum wheat. 

Table 2. — Numbers of flowers per head and per variety of durum wheat bloom- 
ing between stated hours of the day within stated periods in June and 
July, 1914, at the Minnesota Agricultural Experiment Station. 

KUBANKA. 



Head No. 


Flowers blooming between 


Period of blooming. 


6 p. m. and 7 a. m. 


7 a. m. and 12 m. 


12 m. and 6 p. m. 


I 
2 

3 
4 


27 
12 
20 
18 


8 
19 
13 

9 


2 
8 
3 
9 


June 27-July 3 
June 27-July 3 
June 27-July 2 
June 29-July 3 


Total 


77 


49 


22 




ARNAUTKA. 


I 

2 

3 
4 
5 


25 
30 
33 
19 
27 


16 
16 
15 
II 
10 




10 
7 
5 


June 28-July 2 
June 28-July 2 
June 29-July 3 
June 29-July 3 
June 30-July 4 


Total 


134 


68 


22 




Total two varie- 
ties 


211 


117 


44 









These results on the durum wheats show for both varieties a 
greater amount of blooming at night. For Kubanka the difference 
is not large, being 77 at night and 71 in the day, while for Arnautka 
about three-fifths of the blooming takes place at night, there being 
134 at night to 90 in the day. Both varieties show most of their day 
blooming in the forenoon, the forenoon and afternoon bloomings 
being 49 and 22 for Kubanka and 68 and 22 for Arnautka. 

In Table 3 are shown the observations made on two varieties of 
winter wheat. 



146 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 3. — Number of flowers per head and per variety of winter wheat bloom- 
ing between stated hours within stated periods in June, 1914, at the 
Minnesota Agricultural Experiment Station. 

KHARKOV. 



Head No. 


Flowers blooming between 


Period of blooming. 


6 p. m. and 7 a. m. 


7 a. m. and 12 m. 


12 m. and 6 p. m. 


I 
2 

3 
4 
5 


25 
29 
33 
36 
42 


17 
II 
16 
22 
18 


23 
13 
29 
20 
18 


June 18-23 
June 19-24 
June 18-24 
June 19-24 
June 19-24 


Total 


165 


84 


103 











TURKEY. 



I 


14 


14 


17 


June 20-25 


2 


22 


8 


II 


June 19-24 


3 


12 


16 


13 


June 19-24 


4 


13 


16 


II 


June 19-24 


5 


18 


16 


II 


June 18-24 


Total 


79 


70 


63 




Total two varie- 










ties 


244 


154 


166 





The results for the Kharkov variety are 165 night bloomings and 
187 day; for the Turkey variety, 79 night bloomings and 133 day. 
The forenoon and afternoon bloomings are 84 and 103 respectively 
for Kharkov, and 70 and 63 for Turkey. In both of the winter 
varieties a majority of the flowers open in the daytime and there is 
no consistent preponderance of either forenoon or afternoon bloom- 
ing, the totals for the two varieties being 154 forenoon and 166 after- 
noon. The total of all flowers of both varieties observed is slightly 
greater for the afternoon than for the morning. The observations 
on the winter wheats were made necessarily on different days from 
those on the spring wheats, as the blooming time of winter wheats is 
earlier in the season than that of spring wheats. Differences in the 
climatic conditions of the two periods may have had some influence 
on the time of blooming of the flowers. 

There were under observation at the Minnesota Agricultural Ex- 
periment Station 1,500 flowers in all. Seven varieties belonging to 
three distinct types of wheat were represented. Of the flowers on 
which notes were taken 785 bloomed at night (that is, between 5 p.m. 
and 7 a.m.), while 715 bloomed in the day (that is, between 7 a.m. 



LEIGIITY & IIUTCHESON : BLOOMING OF VVIIEAT. 



and 6 p.m.). Of those blooming during the day, 437 bloomed be- 
tween 7 a.m. and 12 noon, while 278 bloomed between 12 noon and 
6 p.m. 

A summary of Tables i, 2 and 3 is made in Table 4. 



Table 4. — Xumbcr of flozvcrs of different types and varieties of wheat bloom- 
ing during different periods at the Minnesota Agricultural Experiment 

Station. 



Type and variety. 


Total number 

of flowers 
under observa- 
tion. 


Number of flowers blooming between — 


5 p. m. and 
7 a. m. 


7 a. m. and 
12 m. 


12 m. and 
6 p. m. 


T, otdl, day. 


Common spring : 












"Velvet Chaff" 


218 


115 


89 


14 


103 


Haynes Bluestem 


214 


138 


53 


23 


76 


Glyndon Fife 


132 


77 


24 


31 


55 


Total 


564 


330 


166 


68 


234 


Durum : 












Kubanka 


148 


77 


49 


22 


71 


Arnautka 


224 


134 


68 


22 


90 


Total 


372 


211 






161 


Winter : 












Kharkov 


352 


165 


84 


103 


187 


Turkey 


212 


79 


70 


63 


133 


Total 


564 


244 


154 


166 


320 


Grand total 


1,500 


785 


437 


278 


715 



It thus appears that under the conditions existing when and where 
these observations were made, about half of the blooming of wheat 
flowers occurred between 7 a.m. and 6 p.m. The other half occurred 
some time between 6 p.m. and 7 a.m., but it is not known whether 
blooming took place during the darkness of night or in the hours of 
twilight and of light before and after observations were made. It 
is probable, however, that much of this blooming occurred in the 
early morning about the time of sunrise, which was about 2^ hours 
before the first observations w^ere made. This conclusion is sup- 
ported by the statement of Hays:- "The floret (of wheat) usually 
opens about dawn, and closes again within an hour." 

OBSERVATIONS ON TIME OF BLOOMING AT ARLINGTON FARM, ROSSLYN, VA. 

Observations on time of blooming of wheat flowers at Arlington 
Experiment Farm, Rosslyn, Va., here reported were made on seven 

2 Hays, Willet M. Plant breeding. U. S. Dept. Agr., Div. Veg. Phys. & 
Path, Bui. 29, p. 50. 1901. 



148 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



varieties of wheat. These included three varieties of the soft red 
winter type, one variety of the soft white winter type, one variety of 
the hard red winter type, and two varieties of the hard red spring 
type. The varieties of the hard red spring type, owing to cHmatic 
conditions in this section unsuited to spring-sown wheats, were here 
sown in the fall, at the regular time for sowing winter wheats. Class- 
ification, names, and descriptions of the varieties used follow. 

Soft red winter type: 

Dietz, bearded, glabrous white chaff, soft red kernels. 
Fultz, beardless, glabrous white chaff, soft red kernels. 
Mealy, beardless, pubescent white chaff, soft red kernels. 

Soft white winter type: 

Giant Squarehead, bearded, glabrous white chaff, soft white or amber 
kernels. 

Hard red winter type : 

Turkey, bearded, glabrous white chaff, hard red kernels. 

Hard red spring type (grown as winter) : 

Bluestem (Minn. No. 169), beardless, pubescent white chaff, hard red 
kernels. 

Fife (Minn. No. 163), beardless, glabrous white chaff, hard red kernels. 

The results of the observations made at Arlington Farm are re- 
corded in Tables 5 and 6. 

Table 5. — Number of flowers per head and per variety of different types of 
wheat blooming between stated hours within stated periods in May 
and June, 1914, at Arlington Farm.^ 



DIETZ (selection NO. I3356). 



Total 
flowers 

per 
head. 


Flowers blooming between 


Total 
day 
bloom- 
ing. 


Period of blooming per head 
(1914). 


Dura- 
tion of 

bloom- 
ing, 
hours. 


5 P- m. 

and 
7 a. m. 


7 a. m. 
and 
12 m. 


12 m. 
and 
5 p. m. 


51 
48 

51 
53 
44 


28 
18 
26 
20 
19 


4 
14 
II 
21 

9 . 


19 
16 
14 
12 
16 


23 
30 
25 
33 
25 


5 p. m. May 26 to 10 a. m. May 30 
5 p. m. May 26 to 4 p. m. May 29 
5 p. m. May 26 to 10 a. m. May 30 

4 p. m. May 27 to 10 a. m. May 30 

5 p. m. May 26 to 7 a. m. May 29 


89 
71 
89 
66 
62 


247 


III 1 59 


77 


136 




75-4 


FULTZ (selection NO. I3360). 


56 
53 
59 
51 
36- 


28 
31 
26 
33 
21 


13 
5 

10 
8 
6 


15 
17 
23 
10 
9 


28 
22 
33 
18 

15 


5 p. m. May 26 to 10 a. m. May 30 
5 p. m. May 26 to 7 a. m. May 29 
5 p. m. May 26 to 5 p. m. May 29 
5 p. m. May 26 to 10 a. m. May 30 
4 p. m. May 27 to 10 a. m.. May 30 


89 

62 
72 
89 
66 


255 


139 


42 


74 


116 




75-6 



LEIGHTY & IIUTCHESON : BLOOMING OF WHEAT. I49 
Table 5. — Number of flowers per head and per variety, etc. — Continued. 



MEALY (selection NO. . 



Total 


Flowers blooming between 


Total 




Dura- 
tion of 
bloom- 
ing, 

hours. 


flowers 

per 
head. 


s p m. 

and 
7 a. m. 


7 a. m. 
and 
12 m. 


12 m. 
and 
5 p. m. 


day 
bloom- 
ing. 


Period of blooming per liead 
(1914). 


52 
38 

54 
61 

55 


21 
16 
23 
18 

27 


14 

7 
15 
18 
II 


17 
15 
16 

25 
17 


31 
22 

31 

43 
28 


5 p. m. May 26 to 11 a. m. May 29 
II a. m. May 27 to 3 p. m. May 29 
4 p. m. May 27 to 10 a. m. May 30 
7 a. m. May 27 to 10 a. m. May 30 
4 D. m. May 26 to 10 a. m. May 30 


66 
52 
66 

75 
90 


260 


105 


65 


90 


155 




69.8 


GIANT SQUAREHEAD (SELECTION NO. I3367-8). 


32 
30 
28 

30 

30 


14 
13 
II 

14 

12 


II 

7 
5 

6 
8 


7 
10 
12 
10 
10 


18 
17 
17 
16 
18 


5 p. m. May 26 to 9 a. m. May 29 
5 p. m. May 26 to 3 p. m. May 29 
5 p. m. May 26 to 7 a. m. May 29 
II a. m. May 27 to 3 p. m. May 29 
9 a. m. May 27 to 9 a. m. May 29 


64 
70 
62 
52 
48 


150 


64 


37 


49 


86 


59-2 


TURKEY (selection NO. 1 3389). 


45 
36 
43 
55 
57 


22 
20 
20 
24 
27 


II 
7 
9 

14 


12 
9 
14 
17 
21 


23 
16 

23 
31 
30 


4 p. m. May 27 to 10 a. m. May 30 

7 a. m. May 28 to 10 a. in. May 30 

4 p. m. May 27 to 10 a. m. May 30 

8 a. m. May 27 to 10 a. m. May 30 

5 p. m. May 26 to 10 a. m. May 30 


66 
51 
66 
74 
89 


236 


113 


50 


73 


123 




69.2 








bluestem 


(MINNESOTA NO. 169).^ 




36 
27 
28 

24 
32 


20 
18 
19 

6 
8 


10 
4 
4 

6 

7 


6 
5 
5 
12 

17 


16 
9 
9 
18 
24 


2 p. m. June i to 12 m. June 4 
5 p. m. June i to 7 a. m. June 5 
5 p. m. June i to 7 a. m. June 5 
5 p. m. June i to 12 m. June 4 
2 p. m. June i to 12 m. June 4 


70 
86 

86 
67 
70 


147 


71 


31 


45 


76 




75.8 



" Some slight inaccuracies exist in Table 5, as can be seen by comparison 
with Tables 7 and 8. The flowers blooming in the observation period from 11 
a.m. to 3 p.m. on May 27, and 11 a.m. to 4 p.m. on June 2 are included in this 
summary as blooming between 12 m. and 5 p.m. Again on May 28 the final 
observation was made at 7 p.m., and on May 30 at 6 p.m. and not at 5 p.m., 
while the morning observation on May 30, when the blooming period was nearly 
done, was at 10 a.m. The afternoon period is slightly favored, but the errors, 
small in any case, are believed to at least partially counterbalance each other. 



150 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 5. — Number of flowers per head and per variety, etc. — Concluded. 

FIFE (MINNESOTA NO. 163).^ 



Total 


Flowers blooming between 


Total 






Dura- 


flowers 
per 
head. 


5 p. m 
and 
7 a. m. 


7 a. m. 
and 
12 m. 


12 m. 
and 
5 p. m. 


day 
bloom- 
ing. 




Period of blooming per head 
(1914). 


tion of 
bloom- 
ing, 
hours. 


42 


24 


II 


7' 


18 


5 P- 


m. June i to 5 p. m. June 5 


96 


36 


16 


10 


10 


20 


5 P- 


m. June i to 5 p. m. June 5 


96 


40 


22 


■7 


II 


18 


12 m 


June 2 to 5 p. m. June 5 


77 


41 


24 


10 


7 


17 


5 P- 


m. June i to 5 p. m. June 5 


96 


23 


18 


5 




5 


5 P- 


m. June 3 to 5 p. m. June 5 


48 


182 


104 


43 


35 


78 




82.6 



* Morning observation on these varieties was made at 8 a.m., so that night 
period is from 5 p.m. to 8 a.m. and day period from 8 a.m. to S p.m. 



Table 6. — Total number of flowers under observation, flowers blooming at 
night, in the forenoon and afternoon, in the entire day, and average 
duration and range of blooming period per head of the seven 
varieties of four types of wheat at Arlington Farm, May 
and June, 1914. 



Type and variety. 


Total 
flowers 


Flowers 
bloom- 
ing be- 


Flowers blooming during 
day between — 


Average 
duration 

of 
bloom- 
ing, 
hours. 


under 
obser- 
vation. 


tween 
5 P- m. 

and 
7 a. m.^* 


7 a. m.a 

and 
12 m. 


12 m. 
and 
5 P- m. 


Total 
day. 


Soft red winter: 

Dietz 


247 
255 
260 


Ill 


59 
42 
65 


77 
74 
90 


136 
116 


75-4 
75-6 
69.8 


Fultz 


139 
105 


Mealy 


155 




Total or average for type .... 


762 


355 


166 


241 


407 


73-6 


Soft white winter: 

Giant Squarehead 


150 


64 


37 


49 


86 


59-2 




Hard red winter: 

Turkej^ 


236 


113 


50 


73 


123 


69.2 




Total or average for winter type 


1,148 


532 


253 


363 


616 


69.8 


Hard red spring: 


147 
182 


71 
104 


31 
43 


45 
35 


76 
78 


75-8 
82.6 


Fife 


Total or average for spring type 


329 


175 


74 


80 


154 


79.2 


Grand total or average 


1.477 


707 


327 


443 


770 


72.5 



a.m. for the Bluestem and Fife. 



The detailed data taken on each of the 35 heads of wheat under 
observation are presented in Table 5, as are also totals for each va- 



LEiGiiTv & iiutcheson: blooming of wheat. 151 

riety. The totals for the different varieties, grouped and summarized 
according to type, and a summary of all observations made on num- 
bers of flowers blooming in the respective periods appear in Table 6. 

Of the 247 flowers of the Dietz variety under observation, iii 
bloomed at night, here considered as being between 5 p.m. and 7 a.m. ; 
•59 bloomed in the forenoon, here considered as being between 7 a.m. 
and 12 m. ; while 77 bloomed in the afternoon, here considered as 
being between 12 m. and 5 p.m., the total for the day being 136. 

Of the 255 flowers of the Fultz variety, 42 bloomed in the forenoon 
and 74 in the afternoon, a total of 116 in the day as compared with 
139 at night. This is one of the two varieties in which the night 
blooming was greater than the day blooming. 

Of the 260 flowers of the Mealy variety, 65 bloomed in the fore- 
noon and 90 in the afternoon, a total of 155 in the day as compared 
with 105 at night. 

These three varieties just reviewed are of the soft red winter type. 
For this type the totals are 166 bloomings in the forenoon and 241 
in the afternoon, a total of 407 in the day as compared with 355 at 
night. 

The only representative of the soft white winter type of wheat is 
the Giant Squarehead, a bearded variety with the so-called square, 
clavate head. On the heads of this variety there were smaller num- 
bers of flowers than in any other of the true winter wheats. Of the 
150 flowers on the 5 heads 37 bloomed in the forenoon and 49 in the 
afternoon, a total of 86 in the day as compared with 64 at night. 

The only representative of the hard red winter type of wheat is 
the Turkey. Of the 236 flowers here under observation 50 bloomed 
in the forenoon and 73 in the afternoon, a total of 123 as compared 
with 113 at night. 

Bluestem and Fife belong to the hard red spring type of wheats, 
but were here grown as winter wheats. They bloomed somewhat 
later than the true winter wheats and in their period of blooming 
conditions for observation were not so good as in the earlier period. 
It seemed also that being grown out of their usual environment they 
furnished somewhat less favorable material for study. The data 
obtained agree with those on the winter types. On these the first 
morning observation was made at 8 a.m. instead of 7 a.m. Of the 
147 flowers of the Bluestem variety observed 31 bloomed in the fore- 
noon and 45 in the afternoon, a total of 76 in the day as compared 
with 71 at night. Of the 182 flowers of the Fife variety 43 bloomed 
in the forenoon and 35 in the afternoon, a total of 78 in the day, while 



152 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

a larger number, 104, bloomed at night. This greater night bloom- 
ing and the approximate equality of the day and night bloomings in 
the Bluestem variety is possibly due to the later hour of the first 
morning observation, although it agrees with the results obtained in 
the Fultz variety of winter wheat. 

The totals for all winter varieties are, forenoon, 253 ; afternoon,* 
363; day, 616; night, 532; w^hile for the spring varieties they are re- 
spectively 74, 80, 154, and 175. 

In each variety except Fultz and Fife the total number of day- 
opening flowers is larger than the total number of those opening at 
night. The number of those opening in the afternoon is appreciably 
larger in each case, except Fife, than the number of those opening in 
the morning.. 

The data here recorded for the true winter wheats correspond 
more closely to those obtained for fall-sown wheat than to those ob- 
tained for spring-sown wheat at the Minnesota station. At the latter 
place the greater number of the common spring and durum wheat 
flowers opened at night, while the forenoon blooming was greater 
than the afternoon. The winter wheats at the latter place, however, 
bloomed more largely in the daytime, the larger number of flowers 
of the Kharkov variety blooming in the afternoon and of the Turkey 
in the forenoon. The Fultz variety at Arlington gives results incon- 
sistent with the other winter varieties, although observations were 
made on it during the same period as on the other varieties. In Fultz 
a somewhat larger number of flowers opened at night than in the day, 
while the afternoon blooming as in the other varieties was greater 
than the forenoon. This difference is possibly due to causes asso- 
ciated with the variety, although for one head of the five the day 
blooming was larger and in another equal to the night blooming. 

The whole series of observations seems to show that the time of 
blooming of wheat depends to some extent upon the variety. It can 
not be concluded, however, that this is the principal factor involved. 
There is also some evidence that the different environmental condi- 
tions of the two places of observation have influenced the time of 
blooming. 

It is interesting to note in this connection that Salmon,^ describing 
conditions in South Dakota, says : It is exceptional to find wheat in 
bloom after 7 a.m. under normal conditions.'* 

As these observations were made to determine the time of bloom- 
ing of wheat flowers the causes of the differences observed were not 

3 Salmon, Cecil. Sterile florets in wheat and other cereals. In Jour. Amer. 
Soc. Agron., 6: 24-30. 1914. 



LEIGHTY & HUTCHESON: BLOOMING OF WHEAT. 



determined. Temperature is possibly an important factor in deter- 
mining the blooming time. Fruwirth"* states that When the tem- 
perature at 4:30 a.m. is above 14° C. the blooming begins at this 
hour." A lower temperature at this hour must then delay blooming. 
Low temperature was not a factor in delaying morning blooming at 
Arlington. 

Table 7. — Time of blooming of zvhcat flozvers on 2$ heads under observation 
from 4 p.m. May 26 to 10 a.m. May 30, igi4 at Arlington Farm, as 
indicated by number of flowers observed while in bloom, day 
and hour of blooming, and numbers blooming unobserved 
within stated periods. 



r lowers ouserved wnilc 


• 

in Diooin* 


Flowers not observed while in bloom. 


Time. 


Number. 


Period in which blooming occurred. 


Number. 


May 26: 








4 P- m 


2 






May 27 : 








7 a. m 


19 


May 26, 5 p. m., to May 27, 7 a. m. 


110 


8 a. m 


33 


May 27, 7 a. m. to 9 a. m. 


2 


10 a. m 


2 


May 27, 9 a. m. to 10 a. m. 


8 


3 P- m 


23 


May 27, II a. m. to 3 p. m. 


96 


4 P- m 


77 






5 p. m 


5 






May 28: 










3 






7 a. m 


28 


May 27, 5 p. m., to May 28, 7 a. m. 


164 




62 








6 


May 28, 7 a. m. to 10 a. m. 


2 


II a. m 


22 


May 28, 9 a. m. to 11 a. m. 


50 


12 m." 


I 






7 p. m 





May 28, 12 m. to 7 p. m. 


112 


May 29: 










I 






7 a. m 


2 


May 28, 8 p. m., to May 29, 7 a. m. 


180 




9 








35 






II a. m 


4 








4 






3 P- m 




May 28, 12 m., to 3 p. m. 


40 


4 P- m 


\ 






5 P- m 








May 30: 








9 a. m 


I 






10 a. m 


3 


May 28, 6 p. m., to May 30, 10 a. m. 


34 




350 




798 



" No observations made between 12 m. and 7 p.m. this day. 



Blooming notes were taken at Arlington Farm on 1,477 wheat 
flowers. Of these, 454 were observed either in the actual process of 

"* Fruwirth, C. Die Zuchtung der landwirtschaftlichen Kulturpflanzen. Band 
4, S. 107. Paul Parey, Berlin, 1910. 



154- 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



blooming or, owing to the frequent observations made, so soon after 
such blooming that the actual time could be recorded. In Tables 7 
and 8 are recorded the numbers observed at the different hours of 
observation on the several days during which the flowers of these 
wheat heads were blooming, and also the numbers blooming within 
certain periods as determined by observations made at the beginning 
and end of these stated periods. These latter figures are set opposite 
the others so that the total number of bloomings may appear and thus 
indicate how dependable are the former records as indicating the 
actual blooming times of wheat flowers. In case of flowers observed 
while in bloom, bloomings taking place 30 minutes before or 30 min- 
utes after an hour are included in the records as of that hour. In 
case of flowers not observed while in bloom the actual times recorded 
in each case marks the beginning and end of the period. 

Table 8. — Time of blooming of wheat flowers on 10 heads under observation 
from 2 p.m., June i to 3 p.m., June 5, 1914, at Arlington Farm, as 
indicated by numbers of flowers observed while in bloom, day 
and hour of blooming, and numbers blooming unobserved 



within stated periods. 


Flowers observed while in bloom. 


Flowers not observed while in bloom. 




Time of observation. 


Number. 


Period In which blooming occurred. 


'Number. 


June I : 








2 p. m 


II 






3 P- m 


I 






June 2: 








8 a. m 


II 


June I, 5 p. m., to June 2, 8 a. m. 


48 




22 








14 






II a. m 


2 






2 p. m 


I 






4 P- m 


2 


June 2, II a. m. to 4 p. m. 


28 


June 3 : 










3 


June 2, 5 p, m., to June 3, 8 a. m. 


53 


9 a. m 


I 






I p. m 


3 








4 


June 3, 12 m. to 2 p. m. 


16 


3 P- m 


7 






4 P- m 


3 






June 4: 








8 a. m 


I 


June 3, 5 p. m., to June 4, 8 a. m. 


74 




2 








3 






II a. m 


I 






June 5: 








8 a. in 


I 






10 a. m 


3 






II a. m 


3 






2 p. m 


4 


June 5, II a. m. to 2 p. m. 


6 


3 P- m 








Totals 


104 


225 



LEIGIITY & KUTCIIESON: BLOOMING OF WHEAT. 



The data in Tables 
5 and 6 can not be 
derived directly from 
Tables 7 and 8 be- 
cause of the slightly 
different methods em- 
ployed in recording 
the time of blooming 
by hours and by pe- 
riods. 

In Table 7 are 
shown the detailed 
observations made on 
25 heads between 4 
p.m. ]\Iay 26 and 10 
a.m. ^lay 30, the 

h o 1 e period of 
blooming of the flow- 
ers on these heads. 



time: or da y 



-p. M. 

3 






























u 





































4 









1 














J 


L 







4 














4 


V 







4 














1 




, 






















♦ 

) — 






















—f— 
















c 








c 






s 




— i 
-/— 








> f 

vL 























Fig. II. Flowers observed in the actual process of 
blooming at the several hours of the day on 25 heads 
(solid line), and 10 heads (broken line) under obser- 
The actual blooming vation at Arlington Farm, 
time was recorded on 



TIME or DA y 




Fig. 12. Combination of line of figure 11. 



350 out of 1,148 of 
the flowers on these 
heads. 

In Table 8 are 
shown the detailed 
observations made on 
10 heads of wheat be- 
tween 2 p.m. June i to 
3 p.m. June 5, 1914- 

In Table 9 the 
numbers recorded as 
blooming on the sev- 
eral hours of obser- 
vation in Tables 7 
and 8 are combined 
and set down oppo- 
site the hour of 
blooming without re- 
gard to the day of 
blooming. These 



156 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

data are then shown graphically in figures 11 and 12. In figure 11 
the solid line represents the number of flowers observed in. the actual 
process of blooming at the several hours of the day on the first lot 
of 25 heads under observation, while the broken line represents the 
same data for the second lot of 10 heads. The combined data for 
these two lots are shown graphically in figure 12. 

Table 9. — Number of flowers observed in the actual process of blooming at the 
different hours of the day on 2$ wheat heads from 4 p.m., May 26, to 10 
a.m.. May 30, 191 4; on 10 wheat heads from 2 p.m., June i, 
to 3 p.m., June 5, 1914; and totals for these two periods. 



Time. 


Flowers observed blooming. 










On 25 heads. 


On 10 heads. 


Totals. 


6 a. m 


4 




4 


7 a. m. . . . • , 


49 




49 


8 a. m 


104 


16 


120 


9 a. m 


36 


25 


61 




II 


20 


31 




26 


6 


32 




5 




5 


I p. m 




3 


3 


2 p. m 




20 


20 


3 P- m 


24 


9 


33 


4 P- m 


83 


5 


88 


5 P- m 


8 




8 


Totals 


350 


104 


454 



From these tables and figures it is evident that blooming was taking 
place at most hours of the day, but that the major part of it occurred 
at rather definite periods. The data indicate, when both the flowers 
observed to open and those not actually observed to open are consid- 
ered, that there is (i) a morning period of extensive blooming, ex- 
tending from about 7 to 9, (2) on at least some days a second fore- 
noon period about 11 o'clock when the number of flowers blooming 
is less than during the first period, probably due to the period being 
shorter rather than to a decreased rate, and (3) a period about the 
middle of the afternoon, apparently most intense about 4 o'clock, 
beginning about 2 or 3 o'clock, according to conditions. This after- 
noon period is of about the same length as the early forenoon period 
and seems to be fully as intense, as many or more flowers blooming 
then as in the first period of the day. The number actually recorded 
as observed to open in this period is not so high because afternoon 
observations were not made on the second day. The number of 



LEIGHTV IIUTCHESON : BLOOMING OF WHEAT. 



flowers blooming after this third period and before dark is probably 
not large, for on one day when observations were made at 7 p.m. no 
flowers were seen to open. This also agrees with general experience 
at Arlington, very few flowers being observed to open as twilight 
approaches. 

It is not known whether or not there were periods of blooming in 
the darkness of night. It seems more probable that most if not all 
of this night " blooming occurred both in Minnesota and at Arling- 
ton in the early morning about sunrise, which is between 4 : 30 and 
5 : 00 o'clock at this time of year. 

With regard to periods of blooming of wheat flowers Fruwirth 
states :^ 

" When the temperature at 4 : 30 a.m. is above 14° C. the blooming begins at 
this hour. Many flowers bloom then from this time to 5 : 30, while from this 
time until 9 : 00 the number is less. Very many bloom from 9-10 a.m., while 
very few bloom from 10 to 2: 30 p.m. From 2: 30 to 3 : 30 the number is again 
large, while from 3 : 30 to 7 : 00 p.m. it is again small. The principal blossom- 
ing time of the morning, which is made up of a preceding and succeeding 
blooming time, of which the first or the second may be the stronger, is followed 
in the afternoon by a later blooming time which approaches in amount to the 
weaker part of the morning blossoming time. (Translation by C. E, L.) 

The periods of time during which the flowers under observation on 
each head were blooming is given in connection with the detailed 
blooming data. In the records of the Minnesota observations only 
the days on which blooming began and ended are given, these appear- 
ing in Table i, 2, and 3. 

The periods of blooming were longest for the winter wheats and 
Kubanka of the durums, all these averaging more than 6 days. Ar- 
nautka durum had the next longest period, 5 days. The common 
spring wheats had no head with a period of blooming of more than 
4 days, and the average for all heads of the 3 varieties was about 3 
days. The period of bloom of the heads of these three common 
spring varieties under observation began later than that for the other 
varieties, July i, and was completed more rapidly. The longer 
period of blooming is possibly due to less favorable weather condi- 
tions in the earlier periods, for it is frequently observed that cool 
weather delays or prevents blooming. 

The data showing the periods of blooming for the heads under 
observation at Arlington are given in detail for each head in Table 
5, and the average for each variety is presented in Table 6, together 
with the range. In observations here recorded the periods of bloom- 

2 Loc. cit., S. 107,- 108. 



158 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

ing are expressed in hours, the data taken allowing such an approxi- 
mation. 

The periods for the different heads range from 48 to 96 hours. 
The average for all heads is 72.5 hours. The average duration for 
the different varieties ranges from 59.2 hours for Giant Squarehead, 
on which the number of flowers per head is low, to 82.6 hours for 
Fife. Turkey and Mealy average 69.2 and 69.8 hours respectively, 
while the average durations for Dietz, Fultz, and Bluestem are prac- 
tically the same, being respectively 75.4, 75.6, and 75.8 hours. 

The period of blooming of the flowers on a wheat head may vary 
from 2 to 7 days. The usual time when conditions are favorable is 
about 72 hours or 3 days. 

SUMMARY. 

At the Minnesota Agricultural Experiment Station and at Arling- 
ton Farm the time of blooming of 2,977 wheat flowers on 69 heads 
were recorded. Of these flowers 1,492 bloomed at night (from 5 or 
6 p.m. to 7 or 8 a.m.), while 1,485 bloomed during the day. Of those 
blooming during the day 764 bloomed before noon and 721 bloomed 
after noon. 

At Minnesota 70 more flowers bloomed at night than in the day, 
while at Arlington 63 more flowers bloomed in the day. 

Some differences were observed in time of blooming that may be 
associated with varietal differences. 

Two periods in the day of extensive blooming of wheat flowers 
were determined, the first a morning period from about 7 to 9, and 
the second a period about the middle of the afternoon. A secondary 
morning period about 11 occurs on at least some days. There are 
one or more periods at night or in the early morning, the exact time 
not being determined, but probably in the early morning. 

The duration of blooming of the flowers on a wheat head may range 
from 2 to 7 days, the usual time being about three days. 

The results of these observations should serve to correct the erro- 
neous impression of many that wheat flowers always blooili very early 
in the morning (apparently true under some conditions) and that it is 
necessary to visit such plants at very early hours in order to secure 
opening anthers. 

2. Natural Fertilization of Emasculated Wheat Flowers. 

In this study flowers on a number of heads of several varieties of 
wheat were emasculated before their pollen was mature and left with- 



LEIGHTY & HUTCIIESON : BLOOMING OF WHEAT. 



out covering. Flowers on other heads of some of the same varieties 
were similarly emasculated and covered, at Minnesota with soft 
tissue paper held in place by light cord, at Arlington with paraffined 
(glassine) paper bags tied in place, these being considered as checks. 
The heads thus treated at both places were scattered at irregular in- 
tervals in rod rows, sown about i foot apart, so were always close 
to unemasculated heads. 

Table 10. — Flozvcrs emasculated and seed set on heads of wheat not covered 
and covered after emasculation at the Minnesota Agricultural Experi- 
ment Station in 191 4. 

(The first figure in each instance is number of flowers emasculated, while the 
second is the number setting seed.) 



HEADS NOT COVERED. 



Kharkov 
(A). 


Kharkov 
(B). 


Red 
Fife. 


Haynes 
Bluestem. 


"Velvet 
Chaff." 


Glyndon 
Fife. 


Kubanka. 


Arnautka. 


Totals. 


14. 7 
20, 4 
18. 8 
18, II 
18, 9 
16. 3 
18, 6 


16, 6 
16. 7 
16, 3 
16. 6 
16, I 
16, 6 
20, 10 
16. 3 
16, 4 
16. 7 


22, II 
28, 8 
36, II 


16, 7 
16, 8 
16, 10 
16, 2 
16, II 

16. 5 
16, 12 
16, 
16, 8 

16, 9 


24, 21 
28, 18 
28, 10 
28, 12 
16, 12 

16, 6 
16, 6 
16, 7 
16, 3 
16, II 


28, 10 
28, 12 
16, 7 

' 

16, 
16, 6 
16, 5 
16, 6 
16, 8 
16, 6 


16, 12 
16, 3 
16, 3 
16, 6 
16, 7 
16, 8 
16, 3 
16, 2 
16, 3 
16, 5 


16, 6 
16, 6 

16, 12 

16, II 
16, II 

16, 12 

16, 5 
16, 7 
16, 5 
16, 6 




Totals 
122, 48 


164. 53 


86, 30 


160, 72 


204, 106 


184. 65 


160, 52 


160, 81 


1,240, 
507 


Percent 
39-3 


32.3 


34-9 


45-0 


52.0 


35-3 


32.5 


50.6 


40.9 


HEADS COVERED. 








16, 
16, 
16, 
16, 
16, 
20, 
20, 
16, 
16, 
16, 


18, 
16, 
16, 
18, 
20, 
16, 
16, I 


16, 
16, 
16, 
20, 
16, 
16, I 








Totals 






168, 


120, I 


100, I 






388. 2 


Percent 


1 







I 






0.5 



For this work the varieties of wheat used at the Minnesota station 
were Kharkov (strains A and B), Red Fife, Haynes Bluestem, Vel- 



l60 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

vet Chaff," Glyndon Fife, Kubanka, and Arnautka. The first two 
are strains of hard red winter wheat, the next four are common spring 
varieties, and the last two are varieties of durum. At ArHngton 
Farm the varieties of wheat used for this work were: Fultz, Lan- 
caster, C.I. 3614, Tennessee Fuhz, CI. 1733, CI. 1933, China, Early 
Genesee Giant, Acme (Selection 2), and Kanred. The Early Gene- 
see Giant is a soft white winter variety, the Kanred a hard red winter 
variety. All the other varieties named are of the soft red winter 
type. 

The number of flowers emasculated and the number of seeds set 
on the different heads in the experiments at the Minnesota Agricul- 
tural Experiment Station are shown in Table 10. Kernels were 
formed by 507 of a total of 1,240 flowers on 70 heads emasculated 
and not covered. This is 40.97 percent of the flowers emasculated 
and not covered. When flowers were emasculated and heads covered 
only two kernels were produced by the 388 flowers worked, less than 
I percent. This shows that the error due to incomplete or untimely 
emasculation or the chance introduction of pollen within the wrap- 
pings is very small. 

Where heads were emasculated, pollinated, and covered with tissue 
paper, 41.7 percent of the flowers worked formed seed. This shows 
that the tissue paper does not prevent the formation of seed when 
pollen is present. 

In Table 1 1 are shown the numbers of flowers emasculated and the 
number of seeds set on the different heads employed in the experi- 
ments at Arlington Experiment Farm. Kernels were formed by 
1,103 of a total of 1,324 flowers on 83 heads emasculated and not 
covered. This is 83.3 percent of the flowers emasculated and not 
covered. From 642 flowers on 40 heads emasculated and covered 
with paraffined paper bags 6 kernels only were formed. Three of 
these kernels were harvested from bags that had been torn, indicating 
that perhaps the pollen had entered through the holes in the bags. 

The small number of kernels found on heads protected by these 
paper wrappings and bags indicates the eft'ectiveness of these methods 
of protecting against foreign pollination. In the actual work of 
hybridization practically all of such errors would be avoided if the 
method of emasculating several days before pollinating the flowers is 
followed. At the time of pollination anthers not removed would 
probably be found, or evidence of fertilization might be discovered. 

These results are in accord with those secured by Salmon working 
in South Dakota. He emasculated 199 wheat flowers before the 



LEIGHTY & HUTCHESON : BLOOMING OF WHEAT. 



I6l 



Oi-it-00\rOMO 



Tj-o too roO loio 



00 N <N lo ro 

o o o o o o o 



oooooooo 



ol 



sO O O O 



OOOOOiNOO 



COOMOOOO 



OOOwOONOO 



1 62 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

pollen was ripe and left them exposed in the field without cover. Of 
these, 152, or 76.3 percent, produced grain. A single head similarly 
emasculated, but covered with a bag, produced no grain. 

When wheat flowers are emasculated and not pollinated the glumes, 
apparently some time after the regular time of blooming, open and 
remain open for several days. The style also grows to an abnormal 
length. Opportunity is thus presented for the entrance of pollen. 
When fertilization has taken place the glumes remain closed. It is 
very unusual for one to succeed in securing the fertilization of all of 
the flowers pollinated by hand. Those not fertilized, amounting 
often to 50 percent or more of those pollinated, would remain open 
and at least some of them would be likely to receive foreign pollen 
and be fertilized. 

In view of the results obtained in these experiments there seems no 
doubt that in studies of inheritance in wheat hybrids and in breeding 
operations where hybrids of known parentage are desired, it is nec- 
essary to protect emasculated flowers from undesired pollination. 

That this practive of covering emasculated flowers has sometimes 
not been considered necessary, is evident from the following state- 
ment made by Carleton :^ 

After trying the experiment for some time, the practice of tying paper or 
cloth bags over the cross-pollinated heads has been abandoned. Often the 
head is much injured by the operation, particularly in times of wet weather, 
and there does not seem to be much need of it. After some experience one 
can determine very readily whether there has been any natural cross-pollination 
other than the one intended simply from the nature of the results, and really 
such an instance seems never to have occurred in our experience. 

Others engaged in wheat breeding have also considered it unnec- 
essary to cover the flowers when crossing is being done. It is shown 
by results here reported that this practice is likely to result in unde- 
sired pollinations. Where accurate records of parentage are at all 
essential emasculated flowers should doubtless be protected. 

SUMMARY AND CONCLUSION. 

At the Minnesota Agricultural Experiment Station kernels were 
formed by 507 of 1,240 wheat flowers emasculated and left unpro- 
tected, while at Arlington Farm 1,103 kernels were formed when 
1,324 flowers were similarly treated. Less than i percent of flowers 
protected after emasculation by paper bags or wrappings produced 
kernels. It is necessary to protect emasculated flowers in order to 
prevent undesired pollination. 

G Bailey, L. H. Plant Breeding, p. 294. The Macmillan Co., New York, 1908. 



STEWART : VARIETIES OF SMALL GRAINS. 



163 



THE VARIETIES OF SMALL GRAINS AND THE MARKET 
CLASSES OF WHEAT IN UTAH.^ 

George Stewart. 

In the Slimmer of 191 8 an attempt was made to learn which varie- 
ties of small grains were being grown by the farmers of Utah. This 
Study consisted of two parts ( i ) a field survey in which wheat, oat, 
and barley fields were visited and the variety determined, and (2) 
the collection of samples of these grains from all available local 
sources. These samples were grown on the college farm at Logan, 
Utah, together with 91 lots of oats grown by the writer at Cornell 
University in 191 7, the identification of which Montgomery- re- 
ported last year. These oats and 34 samples collected in Utah and 
southern Idaho were planted for the purpose of classification and 
also to assist in a study of Etheridge's key. As the classification 
work is not completed, it is not now reported. 

The survey, though incomplete, was carried far enough to give 
some interesting data. Oats were classified according to Etheridge's 
key,^ barley according to Harlan's key,* and wheat, so far as possible, 
in accordance with the yet unpublished classification of Ball and 
Clark. Lack of even a tentative key made it impossible to be sure 
of all the varieties of wheat. A variety locally called Touse caused 
particular trouble, as this name occurs in Utah attached to Bluestem, 
Defiance, New Zealand, and to another variety the true name of 
which has not up to date been ascertained. 

Table I shows the results of the survey by counties. It should be 
mentioned that the field survey was made too late to obtain samples 
from the dry-farm fields in some sections. Two-thirds of the dry- 
farm wheat in Utah is Turkey. The tables do not therefore show 
as high a percentage of Turkey as is actually grown. 

1 Contribution from the Department of Agronomy, Utah Agricultural Ex- 
periment Station, Logan, Utah. Read at the eleventh annual meeting of the 
American Society of Agronomy, Baltimore, Md., January 7, 1919, by Dr. F. S. 
Harris. 

- Montgomery, E. G. The identification of varieties of oats in New York. 
/;/ Jour. Amer. Soc. Agron., 10, no. 4, p. 171-174. 1918. 

3 Etheridge, W. C. A classification of the varieties of cultivated oats. N. Y. 
(Cornell Univ.) Agr. Expt. Sta. Memoir 10. p. 79-172, fig. 12-33, pi. 1-22. 1916. 

* Harlan, Harry V. The identification of varieties of barley. U. S. Dept. 
Agr. Bui. 622, 32 p., pi. 1-4. 1918. 



164 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table i. — Varieties of wheat, oats, and barley grown in Utah and the market 
class of each variety (data by counties in number of fields of each 
variety visited in 1918). 

WHEAT. 



County. 



Variety. 


Market class. 


Box 
' Elder. 


Davis. 


Salt 
Lake. 


Tooele. 


Utah. 


Juab. 


Wayne. 


Sevier. 


San 
Pete. 


Cache. 


Total. 


Dicklow 


Common white 




16 


31 




Ill 


7 


4 


25 


42 


37 


263 


New Zealand 


do 






29 




25 




2 


34 


29 


30 


149 


Marquis 


Hard red spring 




4 


6 


8 


10 


15 


I 


I 


3 


41 


89 


Kubanka 


Durum 












2 


3 


68 






73 


Bluestem 


Common white 


22 


12 




6 


1 










31 


72 


Turkey 


Hard red winter 




4 


2 


13 


4 


13 






2 


18 


56 


Gold Coin 


Common white 




3 
















41 


44 


Kofod 


do 










9 


34 








43 


Defiance 


do 


I 


2 


4 










7 


5 


3 


22 


Little Club 


White club 


I. 


4- 


2 




I 










10 


18 




do 


2 




3 






4 


2 






3 


14 


Fife (Jones' Winter) 


Soft red winter 




2 
















5 


7 




White club 




5 


















5 


Lofthouse 


Common white 


3 


















2 


5 


Odessa 


Soft red winter 




I 
















3 


4 


Droubay 


Common white 








4 














4 


Polish 


Durum 






















2 


Ghirka 


Hard red winter 
















2 






2 


Touse 


Common white 












7 


6 


3 


2 




18 


Mixed 


Mixed 








16 














16 








53 


77 


47 


161 


82 


18 


140' 83 


226 


906 



OATS. 



Swedish Select 


Western white 


16 


4 


23 


7 


21 


15 


7 


34 


22 


29 


178 


Lincoln 


do 






4 


3 


6 


7 




2 


2 


3 


27 


Silvermine 


do 












3 






2 


3 


8 


Kherson 


Yellow 








4 






2 








6 


Storm King 


Western white 






f 




2 




2 






I 


5 


Belyak 


do 
















4 






4 


White Tartar 


White 


I 




I 




2 












4 


Monarch selection. . 


Black 


















3 




3 


C. 1. No. 620 


White 








2 




I 










3 


Boswell Winter .... 


Black 












2 










2 


Green Mountain . . . 


White 










2 












2 


Black Tartarian. . . . 


Black 










I 












I 


June 


Western white 












I 










I 


Sparrowbill 


do 






I 
















I 


Wild 


Wild 












I 




I 


2 




4 


Mixed 


Mixed 








6 














6 


Total 




17 


4 


29 


22 


34 


30 


II 


41 


31 


36 


255 





7 


6 


4 


3 


9 


4 




4 




12 


49 


Manchuria 












2 




2 


I 


4 


9 


Nepal (Pearl) 














6 




I 


2 


9 


Utah Winter 




I 






5 












6 


Two-row 
















2 


3 




5 


Total 


7 


7 


4 


3 


14 


6 


6 


8 


5 


18 


78 



STEWART: VARIETIES OF SMALL GRAINS. 



165 



Table 2. — Percentages of leading varieties of small grains in Utah in igi8 
(data from Table i). 



Wheat. 



Variety. 



Percent. 



Oats. 



Variety. 



Percent. 



Barley. 



Variety. 



Percent. 



Dicklow .... 
New Zealand 
Marquis .... 
Kubanka . . . 
Bluestem . . . 

Turkey 

Gold Coin . . 

Kofod 

Defiance. . . . 
Little Club. . 

Touse 

Sonora 

Eight others 
Mixed 



29.0 
16.4 
9.8 
8.1 
7-9 
6.2 
4.8 
4.7 
2.4 
2.0 
2.0 
1.8 
31 
1.8 



Swedish Select 

Lincoln 

Silvermine . . . 

Kherson 

Storm King . . 

Belyak 

Nine others . . 
Mixed 



69.7 
10.6 

31 
2.4 
2.0 
1.6 
8.2 
2.4 



Coast .... 
Manchuria 

Nepal 

Club 

Two-row . . 



62.6 
11.6 
11.6 
7.8 
6.4 



Total : 100.0 



The varieties of wheat common on irrigated farms were Dicklow, 
New Zealand, IMarquis, Bluestem, Defiance, and Touse ; on dry farms, 
Turkey, Marquis, Kofod, Gold Coin, Bluestem, and Sonora. Other 
varieties are not widely known. 

It is interesting to note that Kubanka, one of the spring durums, 
altho originally introduced into the United States for the regions 
of most severe drouth, was found entirely under irrigation on low 
water-logged lands. Farmers reported that other varieties lodged 
and rusted, whereas this variety lodged but did not rust. Farmers 
liked Kubanka on this account, but they have trouble in selling it, as 
millers do not care to handle it because of difficulty in milling. 

Another interesting point is that out of 89 fields of Marquis, 54 
wer£ grown under irrigation. This wheat was brought into Utah 
for a spring grain on the dry farms. It was also peculiar that in most 
cases irrigated Marquis was hard and vitreous, whereas nearly all 
irrigated Turkey wheat was filled with yellowberry to the extent of 
75 percent or more. 

Marquis and Dicklow were accused of shattering. Many of the 
farmers of Utah run cattle on the National forest ranges in summer 
and winter them on straw. These men dislike Turkey and Kubanka 
on account of beards in the straw, which stick in the mouths of the 
cattle and are therefore objectionable. 

It may be of interest to note the jumble of varietal names. In 
Davis County Dicklow was known as Dicklow, Australian Club, Cali- 
fornia Club, and Club ; in Salt Lake County as Excelsior, California 



1 66 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Club, and Club; in Utah County as Dicklow and California Club; 
and in Sevier County as Club, California Club, Dicklow Club, and 
Dicklow. New Zealand was generally known by its true name, but 
was found in Cache County being grown as Bluestem ; in Salt Lake 
County as Ninety-Day; in Wayne and Juab counties as Touse; and 
in Sanpete as Ruby. Bluestem was usually called Bluestem, but was 
found in Cache County called New Zealand ; in Boxelder and Utah, 
Ninety-Day ; in Tooele, Touse and Sonora. Sonora was usually 
called Red Chaff. It occurred as Red Chaff and Sonora in Salt 
Lake County, as Red Fife in Juab, and as Red Russian in Boxelder. 

Kofod has been written Koffoid " in publications of the Utah sta- 
tion and of the United States Department of Agriculture. Relatives 
of the man for whom the grain was named were found and it was 
learned that he and all his people write their name Kofod. Accord- 
ingly this spelling has been adopted by the Utah station and the word 
is so written herein. 

Field agriculturists in Utah have long urged the farmers to stand- 
ardize their varieties, but so long as no grading was done in the State 
this advice was unheeded. In August, 191 7, a Federal grain super- 
vision offfce was established in Salt Lake City. Grading was then 
begun by the Utah-Idaho Grain Exchange. Results for the first year 
have just been completed. In the year ending July 31, 1918, the Utah- 
Idaho Grain Exchange graded 1,747 cars. Table 3 shows the per- 
centage of the total in each class and the percentage of grades in each 
class influenced by "wheat of other classes" and by ''heat damage." 



Table 3. — Percentage of wheat in each class and percentage of grades in each 
class determined by wheat of other classes and by heat damage. 



Class. 



Common variety in each class. 



Percentage of 
total in this 
class. 



Percentage of class 
I graded down because of- 



Wheat of 
other 
classes. 



Heat dam- 
age. 



Hard red spring 

Durum 

Hard red winter 
Common white . 



White club 
" Mixed " . 



Average 



Marquis 

Kuban ka 

Turkey 

New Zealand, California 
Club, Dicklow, Blue- 
stem, Touse 

Little Club 



10.3 

25-1 

19.8 
.8 
44.0 



21.6 
II. 7 



44-7 
46.7 



4-7 
22.6 



•9 

19-5 



5-3 



13.2 



Table 3 shows that 44 percent of the 1,747 cars was graded mixed 
wheat on account of wheat of other classes. Wheat is not classified 



STEWART: VARIETIES OF SMALL GRAINS. 



167 



Table 4. — Percentage of common zvhitc wheat and its subclasses in each grade 
and percentage of each determined by wheat of other classes. 





Common white. 


Hard white. 


Soft white. 


Grade. 


Percentage 

of class in 
grade. 


Percentage of 
grade deter- 
mined by w heat 
of otlier classes. 


Percentage 

of subclass 
in grade. 


Percentage of 
grade deter- 
mined by wheat 
of other classes. 


Percentage 
of subclass 
in grade. 


Percentage of 
grade deter- 
mined by wheat 
of other classes. 


I 

2 

3 
4 
5 

Sample 


139 
56.0 
243 
3-2 

2.3 

•3 


40.8 
60.0 
50.0 


14-3 
53-3 
27.2 

5-2 


3.v5 
87-5 
50.0 


13-8 
56.8 
23-4 
2.6 
3-0 
.4 


42.3 
57-4 
50.0 


Average 




44-7 


1 50.0 




43-7 



as mixed unless there is an admixture of other classes in excess of 10 
percent. No matter how many varieties there may be that fall into 
the same class or subclass, a mixture of these affects neither the class 
nor the grade. Let us take the class common white as an example. 
The survey showed that there are in Utah nine varieties that grade 
common white, four of which are common. Of these nine, seven 
(Dicklow, Bluestem, Kofod, Gold Coin, Lofthouse, Droubay, and 
Touse) are soft white, and two (New Zealand and Defiance) are 
hard white. Bluestem, New Zealand, Defiance, Dicklow, and Touse 
occurred as a mixture in the same field many times. The admixture 
of two or even all of these varieties would have caused neither the 
classification of the wheat as mixed " nor the placing of it in a 
lower grade. Though such mixtures would not disturb the grading, 
they would markedly influence the yield, because New Zealand and 
Dicklow are far better yielders under irrigation than are Touse or 
Bluestem. Defiance also has been a good yielder. In three counties 
the writer made inquiries of fifty farmers concerning their choice of 
the first, second, and third best irrigated wheats. The results are 
shown in Table 5. 



Table 5. — Varieties of wheat preferred by 50 farmers on irrigated farms in 

three counties. 





Choice. 


Total. 


Variety. 










First. 


Second. 


Third. 




Dicklow 


26 


20 


4 


50 


New Zealand 


18 


21 


II 


50 


Defiance 


I 


3 


6 


10 




I 


3 


18 


22 


Marquis 


2 


2 


7 


II 




2 




4 


7 


Total 


50 


50 


50 


150 



l68 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table 5 shows that although many of the farmers consulted were 
not attempting to grow them, they were satisfied in their own minds 
as to which varieties of wheat were best. Without actual data it is 
impossible of course to say which variety would be the highest 
yielder, but judging from fields seen the writer would chose Dicklow, 
New Zealand, and Defiance as the three best varieties for irrigation. 
Dicklow has not been tested by the Utah station, but New Zealand 
and Defiance have been the highest yielders of the varieties grown. 

Table 6 shows the" approximate number of bushels graded down, in 
part because of the influence of wheat of other classes and heat dam- 
age. In all, the grade of 512,320 bushels was influenced. If the 
768,000 bushels that were classified as " mixed " wheat are added to 
this figure the total affected is 1,280,320 bushels, or 73.3 percent of 
all wheat marketed. These figures assume that each car carried just 
1,000 bushels, the minimum set by the Food Administration. These 
are conservative figures, as some held more than the minimum. 



Table 6. — Approximate total number of bushels in each class and the approxi- 
mate number of bushels graded down in the Utah-Idaho Grain Exchange 
in igi8 because of wheat of other classes and heat damage. 



Class. 


Number 
of cars. 


Approximate 
number of 
bushels in 
class. 


Approximate nu 
graded dow 

Wheat of other 
classes. 


mber of bushels 
n because of 

Heat damage. 


Total number 
of bushels. 


Hard red winter 

Common white 

White club 


180 
437 
348 
14 
768 


180,000 

437,000 
348,000 
14,000 
768,000 


38,880 
51.130 
155.560 
6,540 


8,460 
98,760 
3.130 

149,860 


47.340 
149,890 
158,690 
6,540 
149,860 


Total 


1.747 


1,747,000 


252,110 


260,210 


512,320 



Table 7. — Approximate monetary loss due to influence of wheat of other 
classes and heat damage. 



Class. 


Loss due to wheat of 
other classes. 


Loss due to heat 
damage. 


Total loss. 


Hard red spring 

White club ." . 

Mixed 


1 388.80 
511-30 
1.555-60 
65.40 


$ 84.60 
987.60 
31-30 

1,498.60 


$ 473-40 
1,498.90 
1,586,90 
65.40 
1,498.60 




12,521.10 


$2,602.10 


15,123.20 




$8,991.60 










113,114.80 



STEWART: VARIETIES OF SMALL GRAINS. I69 

Table 7 shows the approximate monetary loss to wheat growers 
due to wheat of other classes and heat damage. In making this table, 
it was assumed that the grades reduced were cut only one grade, and 
that only half of this reduction was due to these two factors. This 
places the loss at i cent a bushel for each grade affected. The loss 
was probably considerably greater than this, because some wheat was 
cut more than one grade. Some of the cutting was also influenced 
more than half by these two factors, for the total damage other than 
heat was only 20.2 percent and the percentages of grades influenced 
by moisture, by inseparable foreign matter, and by odor were 1.8 
percent, 2.8 percent, and 0.8 percent, respectively, making a total for 
all wheat of 25.6 percent for these factors as opposed to 28.5 for 
wheat of other classes and heat damage. It is probable that a part 
of the reduction in grade due to test weight, 33.5 percent, was also 
due to light mixtures of grain or weed stems. 

The Yearbook of the United States Department of Agriculture for 
1 91 7 gives the total production of wheat in Utah as 5,650,000 bushels. 
A considerable part of the 1,747 cars were from southern Idaho; 
therefore, the 1,747,000 bushels graded by the Utah-Idaho Grain Ex- 
change does not represent more than 25 percent of the crop, possibly 
much less. In order to arrive at anything like an accurate estimate 
of the growers' losses, it is necessary to multiply the figures in Table 
7 by at least 4. This would place the losses to farmers of Utah and 
southern Idaho at $10,084.40 for grading down due to wheat of other 
classes; at $10,408.40 for grading down due to heat damage; and at 
$35,966.40 due to the classification of 44 percent of the crop as mixed 
wheat. The total loss then is at least $52,458.20 due to the admix- 
ture of unlike varieties and to weed injury. In addition there was 
an average for all classes of 1.58 percent dockage. Some one has to 
pay freight on this useless material from the farm to the warehouse 
at which it is screened out and also the cost of handling on the farm. 
Irrigated farmers had a still greater loss, the dockage being 2.02 
percent on common white, the wheat mostly grown under irrigation. 

SUMMARY. 

1. Varieties of small grain grown in Utah are badly mixed. 

2. Varietal names are frequently misapplied. 

3. The most common varieties of wheat and the ones that seem 
b)est adapted are Dicklow and New Zealand on irrigated farms, and 
Turkey, Kofod, Bluestem, and Gold Coin on the dry farms. Oats 
are almost standardized to the Swedish Select variety. 

4. Market grades substantiated the results of the field survey. 



I/O JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



AGRONOMIC AFFAIRS. 

MEMBERSHIP CHANGES. 

The membership as reported m the March Journal was 515. Smce 
that time 11 new members have been added, 3 have been reinstated, 
and 4 have resigned, a net gain of 10 and a present membership of 
525. The names and addresses of the new and reinstated members, 
the names of those who have resigned, and such changes of address 
as have come to the notice of the secretary or the editor, follow : 

New Members. 

Brockson, W. L, Agr. Serv. Bur., Amer. Agr. Chem. Co., Boston, Mass. 

Bruce, Wm. F., New Vienna, Ohio. 

CowART, I. E., Substation No. i, Beeville, Texas. 

Duncan, J. R., East -Lansing, Mich. 

Hastings, Wm. R., 16 West Mitchell St., Atlanta, Ga. 

Langebacher, R. a.. Farm Crops Dept., Columbia, Mo. 

Megee, C. R., East Lansing, Mich. 

Musgrave, G. W., Agr. Expt. Sta., New Brunswick, N. J. 

Nicolson, J. W., East Lansing, Mich. 

Putnam, G. W., Chatham, Mich. 

Wilson, A, L., County Agr. Agent, Morgan, Utah. 

Members Reinstated. 
Cox, J. F., East Lansing, Mich. 

Raymond, L. C, Macdonald College, Quebec, Canada. 

RiCHEY, F. D., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Members Resigned. 

French, W. L., Wright, A. H., Youngblood, Bonney, 

LOWRY, M. W. 

Changes of Address. 

Chapman, James E., Div. of Soils, University Farm, St. Paul, Minn. 
Dustman, Robert B., Dept. of Soils, Ohio State Univ., Columbus, Ohio. 
Gustafson, a. F., Soil Technology, Cornell Univ., Ithaca, N. Y. 
Hopt, Erwin, Cambridge, Nebr. 

Johnson, Geo. F., 67 W. Tenth Ave., Columbus, Ohio. 

Laude, H. H., Agr. Expt. Sta., College Station, Texas. 

Milton, R. H., 117 Cheapside, Lexington, Ky. 

Murray, James, Nobleford, Alberta, Canada. 

Rueda, Buenaventura, Quinta de los Molinos, Habana, Cuba. 

Smith, Raymond S., Room 653 Agr. Bldg., Univ. of 111., Urbana, 111. 

Stadler, L. J., Farm Crops Dept., Univ. of Mo., Columbia, Mo. 

Thysell, John C, Northern Great Plains Field Sta., Mandan, N. Dak. 

Tinsley, J. D., Box 673, Albuquerque, N. Mex. 



AGRONOMIC AFFAIRS. 



171 



NOTES AND NEWS. 

R. K. Bennett,, formerly assistant professor of farm crops at the 
Kansas State Agricultural College, has been professor and head of 
the department of farm crops in the Idaho college and station since 
September i. 

W. I. Brockson, formerly with the Iowa and Illinois stations, is now 
with the service bureau of the American Agricultural Chemical Com- 
pany, with headquarters at Boston. 

W. P. Brooks, agriculturist of the Hatch (Mass.) station during 
its entire existence and director of the Massachusetts stations since 
1906, has resigned to become consulting agriculturist of these stations, 
F. ^lorse has been appointed acting director. 

AI, O. Bugby has resigned as superintendent of experiment farms in 
Trumbull and Mahoning counties, Ohio, and h^s been succeeded by 
J. P. ^larkley, formerly superintendent of the test farm at Strongs- 
ville, to which position W. H. Reutenik has been appointed. 

Kenyon L. Butterfield, president of the Massachusetts Agricultural 
College, is in Europe as a member of the army overseas educational 
commission. Several college and station men are associated with him 
in this work, including Director E. A. Burnett of the Nebraska sta- 
tion. Director Harry Hayward of the Delaware station, and Professor 
L. E. Call, agronomist of the Kansas station. 

J. P. du Buisson, a member of this society and formerly a graduate 
student at Cornell University, died of sunstroke in Senekal, South 
Africa, July 27, 1918. Since his return to South Africa Mr. du 
Buisson had been engaged in teaching soil chemistry in the University 
of Potchefstroom, South Africa. 

W. F. Gericke of the California station is on leave of absence for 
graduate study. 

A. E. Grantham, agronomist of the Delaware station, is acting 
.director of that station during the absence of Director Hayward in 
Europe. 

C. H. Helm of the department of farm crops, University of Mis- 
souri, has returned to his duties after six months' service in the 
National Army. 

E. A. Hodson of Cornell University has been appointed assistant 
professor of agronomy in the Delaware college. 



172 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



R. R. Hudelson has resumed his work as assistant professor of 
soils in the Missouri college of agriculture, after a year and a half in 
military service. 

E. M. McDonald, assistant professor of farm crops in the Univer- 
sity of Missouri, has returned to his duties after twenty-one months 
of army service. 

George D. Musgrave has been appointed assistant professor of 
agronomy in the New Jersey college of agriculture. 

H. S. Records is home project worker with the rank of assistant 
professor in the Northwest School of Agriculture, Crookston, Minn. 

The Agricultural History Society was organized at Washington, 
D. C, February 14, 1919, to "stimulate interest, promote study, and 
facilitate publication of researches in agricultural history." The 
officers are Dr. Rodney H. True, Bureau of Plant Industry, Wash- 
ington, D. C, president ; Prof. Wm. J. Trimble, Agricultural College, 
N. Dak., vice-president ; and Lyman Carrier, Bureau of Plant Indus- 
try, Washington, D. C, secretary-treasurer. Prof. R. W. Kelsey, 
Haverford, Pa., and O. C. Stine, Office of Farm Management, Wash- 
ington, D. C, are additional members of the executive committee. 
Any one interested in the subject is eligible to membership and is in- 
vited to send his application, with annual dues of v$i.oo, to the secre- 
tary-treasurer. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. May, 1919. No. 5 



A STUDY OF THE RELATION OF SOME MORPHOLOGICAL 
CHARACTERS TO LODGING IN CEREALS.^ 

R. J. Garber and p. J. Olson. 

INTRODUCTION, 

One of the perplexing problems which confronts the cereal plant 
breeder is the production of nonlodging small grains which at the 
same time possess high yielding capacity. In 191 6, a project was 
organized at the Alinnesota Agricultural Experiment Station with 
the object of determining whether some simple morphological char- 
acter is closely correlated with lodging or nonlodging.- With such a 
criterion the matter of studying lodging would be much facilitated, 
since the nonlodging forms could be immediately isolated without 
waiting three or more years to determine the promising selections or 
parental stock. A few investigations bearing on this subject have 
been made. 

REVIEW OF LITERATURE. 

Moldenhawer," working with wheat and barley, found number of 
vascular bundles to be a distinguishing characteristic for different 
sorts and that nonlodging sorts could be selected by means of the 

1 Published with the approval of the Director as Paper No. 171 of the Jour- 
nal series of the Minnesota Agricultural Experiment Station, University Farm, 
St. Paul, Minn. Received for publication April 8, 1919. 

2 The writers are indebted to H. K. Hayes, head of the section of plant 
breeding, Division of Agronomy and Farm Management, for assistance in out- 
lining and carry out this project. 

2 Moldenhawer, K. Die Gesfaszbundelzahl und ihre Bedeutung fiir die 

Lagerung des Getreides. /;/ Zeitsch. Landw. Versuchs. Osterr., 17:886-891. 
J9I4- 

173 



1/4 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



number of vascular bundles. In general, the more nonlodging forms 
contained the greater number of bundles. 

Albrecht* accepted without question the breaking strength of straw 
as an index to lodging. His conclusions are based on individual 
plants of a single variety of winter wheat, grown at Kongsberg, Ger- 
many, in 1905. Evidence is presented showing (i) a fairly high 
correlation between breaking strength and the weight of i cm. of 
straw, (2) some correlation, fairly consistent, between breaking 
strength and total area of a cross section of the vascular bundles, 
(3) some correlation between breaking strength and thickness of 
culms, and (4) little correlation between breaking strength and thick- 
ness of sclerenchyma. 

MATERIAL AND METHODS. 

Selections of varieties and crosses which appeared to be homo- 
zygous for botanical characters were used. Within the various small 
grains the most lodging and most nonlodging forms were selected. 
In all, 15 strains of barley, 7 of oats, 2 of spring wheat, 2 of winter 
wheat, and i of winter rye were studied. 

Most of the material was grown both under field and greenhouse 
conditions. A separate study was made of the morphological char- 
acters of each sort grown under the two environments. Data on 
lodging, yield, and height represent an average of three years' results, 
except where otherwise stated. 

The rod-row plots in the plant-breeding nursery furnished the 
source of the notes on these characters. Each sort was grown on two 
or three systematically distributed plots each of which consisted of 
three or four rod rows. The rank of the various strains as to lodging 
was determined by two notes, one on the percentage of the plot lodged 
and the other on the average degree lodged, i. e., the average degree 
of the angle which the lodged grain made with the normal condition. 
For instance, if half of the plot under consideration was down flat it 
would be noted as follows, — percentage lodged 50, degree lodged 90. 

The material for study^ was collected and fixed after internodal 
growth had ceased, but before the grain was entirely ripe. Sections 

^ Albrecht, K. Untersuchungen iiber Korrelationen im Aiifbau des Weizen- 
lialmes, welche fiir die Lagerfestigkeit des Getreides von Bedeutung sind. In 
Landw. Jahrb., 37 : 617-^72. 1908. 

5 The authors wish to express their appreciation of the aid and helpful sug- 
gestions of Dr. C. O. Rosendahl, of the Botany Division of the University of 
Minnesota, in regard to histological methods and for the kindly interest shown 
in analyzing the data. 



GARBER & OLSON: LODGING IN CEREALS. 



of the culm about a centimeter in length were taken at the places 
indicated (first internode considered that bearing the panicle or spike) 
by means of a razor. After the culm fragments were desilicified and 
embedded in celloidon, sections of from 20 to 30 microns in thickness 
were made. The sections were stained with safranin and Delafield's 
haematoxylin and afterward mounted. Safranin stained the lignified 
tissue a bright red while the phloem was stained blue by Delafield's 
haematoxylin. 

Briefly, the morphological data taken were as follows : diameter 
of culm with a caliper before embedding, number of vascular bundles, 
thickness of culm, thickness of sclerenchyma, and average diameter 
of vascular bundles including their surrounding lignified cells. All 
microscopical measurements except those under oil immersion were 
made by means of a millimeter eye-piece and then reduced to a frac- 
tion of a millimeter. Thickness of culm wall was obtained by 
measuring the average distance from the periphery of a cross section 
to its inner boundary. The heavy-walled, deep-stained cells which 
make up the sclerenchyma tissue found near the periphery were 
measured at several places to obtain their average width or thickness. 
The average diameter of vascular bundles, including their surround- 
ing lignified cells, was obtained by measuring the longest and shortest 
diameter of each of from seven to ten bundles of each individual 
and then computing the average diameter from the measurements 
thus obtained. The number of vascular bundles was ascertained by 
simply counting those which appeared in a cross section of the culm 
(see Plate 6, figure i). 

The foregoing paragraph is a somewhat brief description of the 
treatment accorded each mounted cross section. Each cross section 
represented one plant and each pure-line strain was represented by 
from 8 to 25 cross sections. 

A maceration study was made of the material grown in the green- 
house to determine the average length of the lignified cells. 
Schultze's maceration method was employed. A composite sample 
of from 15 to 25 individuals of each strain was macerated and 
mounted in duplicate and then stained with safranin. Twenty-five 
deeply stained cells on each slide were measured for length, thus 
making fifty measurements for each strain. A study was made of a 
composite sample representing the strain rather than considering 
separately each individual of a strain, as it was found in preliminary 
work that individuals of the same pure line did not differ significantly 
for the character under consideration. 



1/6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table i. — Data on percentage of lodging, degree of lodging, yield, and height 
of plant of various strains of barley, oats, and wheat. 



Nursery 
selection 
No. 


Variety. 


Type. 


Percentage of 
lodging. 




Degree 
lodging. 


■ 


1 Rank. 


Average 

yield, 
bushels. 


Average 
height, 
inches . 


1916 


^^^^ 
1917 


1918 


Ave. 


1916 


1917 


1918 


Ave. 


Barley: 






























IVIanchuria X Svan- 




























hals 


2 -row 





3 





I 





47 





16 


I 


39-2 


39 


II-16-77 


S. African X Man- 




























churia 


6-row 




41 


25 


22 





70 


33 


34 


2 


53-1 


31 


I-16-15 


Servian 


do 






40 


70 


44 


20 


31 


27 


26 


3 


44-3 


32 


II-16-78 


Bohemian X Man- 




























churia 


2-row 





50 


100 


50 





80 


13 


31 


4 


41-5 


37 


I-16-60 


Chicago No. 63 . . . 


6-row 





67 


100 


56 





70 


20 


30 


5 


40.6 


35 


I-16-33 


Lake City 


do 


52 


25 


100 


59 


45 


40 


10 


32 


6 


44.1 


37 


I-16-14 


Trebi 


do 


5 


59 


100 


55 


15 


72 


68 


52 


7 


49.1 


30 


I-16-13 


Lion 


do 


3 


62 


92 


52 


13 


69 


88 


57 


8 


54-3 


30 
























T T A A A 
1—10—44 


Manchuria Hxcel- 






























6-row 


57 


80 


67 


68 


62 


85 


18 


55 


9 


47-3 


38 


1— 10— 


Featherston 


uo 


75 


87 


92 


85 


50 


76 


17 


A Q 

48 


10,40.2 


37 


1—10—3 


Sandrel 


uo 


67 


95 


93 


85 


42 


85 


33 


53 


II 


50.0 


30 


T T A A r- 

1-10-45 




A^ 

do 


66 


92 


95 


84 


72 


89 


37 


00 


12142.6 




II— 16— 13 1 


Svanhals X 2r/ 6r . . 


2 -row 


o2 


63 


100 


02 


1 


83 


53 


70 


13 


41.7 


39 


I-I6-2 


Featherston 


6-row 


88 


59'ioo 


90 


58 


05 


50 


64 


14 


38.9 


31 


I-I6-3I 


Highland Chief. . . 


do 


90 


97 


100 


90 


62 


90 


Q Q 
00 


80 


15 


55-2 


37 


Oats : 




























I-I5-40 


(jrartons 


i3iae 


95 





42 


46 


93 





35 


43 


I 


70.1 


43 


I-06-28 


Dept No. 5168. . . 


Open 


100 


13 


72 


62 


100 


10 


28 


46 


2 


68.6 


38 


I-I5-99 


Swedish Select . . . 


do 


100 


33 


80 


71 


100 


32 


90 


74 


3 77-2 


48 


I-I7-72 


Sixty-Day 


do 






43 


43 






30 


30 


I 


81.3" 


34" 


I-I7-40 


S. P. I. No. 33644- 


do 






48 


48 






60 


60 


2 


71. 1" 


34" 


I-I7-70 


Sixty-Day 


do 






100 


100 






57 


57 


3 


74-9" 


34" 


Wheat : 




























I-01-3 


Odessa 


Winter 





37 




19 





8 




4 


I 


32.9" 


45" 


1-03-68 


Turkey (Cosgrove) 


do 


90 


100 




95 


54 


62 




58 


2 


28. 6« 


37" 


11-06-39 


Preston 


Spring 


6 





67 


24 


15 





20 


12 


I 


27.4 


42 


Check 


Bluestem 


do 


24 


10 


67 


34 


45 


13 


23 


27 


2 


24.8 


43 



« One year only. 



RELATION OF YIELD AND HEIGHT OF PLANT TO LODGING. 

The data from which the rank of the various sorts as to lodging 
was determined are listed in Table i. Here also may be found the 
average yield and height of the sorts studied except winter rye, for 
which no data were available. Under Minnesota conditions the 
winter rye used is one of the most nonlodging cereals. 

It is apparent from the table that there is no correlation either 
between yield and lodging or between height of plant and lodging. 
Barley strain II-16-77 with an average yield of 53.1 bushels stands 
up well, while strain I-16-31 with an average yield of 55.2 bushels 
lodges badly. Similarly comparing heights gives no clew to their 



CAREER OLSON: LODGINC. IN CEREALS. 



Stiffness of straw. For example, consider the two barley sorts 
II-16-77 and I-16-2. Both have an average height of 31 inches, 
but one has stiff straws, while the other has not. Other examples 
easily could be pointed out from the table. It would seem that other 
things being equal the taller, heavier yielding strains, would be more 
likely to fall. Evidently there are other factors of more importance 
in determining the sorts most susceptible to lodging. 

It may be of interest to note that Hordciim- vulgare or Hordeum 
distich urn are not associated exclusively with either lodging or non- 
lodging forms. In each of these two classes both 2-rowed and 6- 
rowed barleys are found. 

CULM MEASUREMENTS AND NUMBER OF VASCULAR BUNDLES. 

Tables 2 and 3 present the assembled average results of the culm 
measurements, average number of vascular bundles, number of indi- 
viduals representing each sort, and the rank of the various strains as 
to nonlodging. 



Table 2. — Average data on culm measurements of barley. 



c 

. 

« t 

■^'^ 
C 
01 

Pi 


Nursery 
selection 
number. 


Field material measured at 4th internode. 


G 


reenhouse material measuied 
internode. 


at 5th 


Number of 
individuals. 


1 Diameter of 
1 culms. 


Thickness of 
culm walls. 


1 Number of 
bundles. 


Total area 
of bundles. 


Area 
of scleren- 
chyma- 


Number of 
individuals. 


Diameter of 
culms. 


Thickness of 
culm walls. 


Number of 
1 bundles. 


Total area 
of bundles. 


Area 
of scleren- 
chyma. 








mm. 


mm. 




sq.mm. 


sq.mtn. 




mm. 


mm. 




sq.mm. 


sq.mm. 


I 


11-16-116° 


13 


4.023 


0.437 


34-15 


0.386 


0-857 














2 


II-16-77 


12 


3-875 


.473 


33-09 


.426 


.708 


25 


3.524 0.597 


35-28 


0.461 


0.545 


3 


I-I6-I5 


15 


4.407 


•448 


35-47 


.428 


-752 


22 


4-273 


.754 


49.78 


-591 


.820 


4 


11-16-78° 


15 


4.207 


.389 


35-40 


.400 


•833 


24 


2.863 


.416 


27.79 


.299 


•459 


5 


I-16-60 


23 


3-496 


-379 


35-43 


.312 


.595 


24 


3-313 


.651 


39-88 


•429 


.608 


6 


I- I 6-33 


19 


4-432 


-433 


43-74 


.462 


.811 


20 


4-095 


.739 


42.55 


• 522 


•736 




I-16-14 


13 


4.362 


.451 


34-46 


.416 


•798 


23 


3-709 


.646 


42.57 


•539 


.719 


\ 


I-16-13 


18 


3-956 


.412 


30.06 


.318 


.674 
















I- I 6-44 


15 


4-193 


.454 


41-87 


.506 


.741 


21 


3.967 


.609 


42.10 


•542 


•735 


10 


I- I 6-8 


12 


4-308 


.434 


40.67 


.491 


.722 


22 


3-618 


.627 


43-00 


-495 


.671 


II 


I-16-3 


13 


4.800 


.492 


37-69 


-580 


1.025 


21 


3-771 


.636 


39.19 


.561 


-723 


12 


I-16-45 


13 


4-131 


.468 


34.08 


.412 


.768 


13 


3.477 


.652 


36.31 


-497 


-654 


^3 


II-16-131 ° 


17 


3.859 


.422 


32.35 


-378 


•634 


15 


5.087 


.800 


41.87 


-539 


I-103 


14 


1-16-2 














24 


3.333 


.551 


28.29 


-381 


.616 


15 


I-16-31 


16 


4-238 


.470 


35.25 


.426 


.852 


19 


3.089 


.610 


37-00 


.378 


-487 



« Two-rowed varieties. 



Considering first the 6-rowed barley selections (Table 2), it is 
evident that the data here presented do not corroborate the finding 
of ^loldenhawer with respect to relation of number of vascular 



178 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



bundles to lodging. Both the greenhouse and the field material show 
the nonlodging forms to possess no more and in several instances a 
smaller number of vascular bundles than the lodging forms. In 
general, the sorts with the largest number of bundles are found 
about midway between the lodging extremes. 

It should be noted that there is not a very close correspondence 
between the field-grown material and that grown under greenhouse 
conditions. The latter also proved to be considerably more variable 
than the former. 

None of the other characters (Table 2), average diameter of culms, 
average thickness of culm wall, average total area of bundles, and 
average area of the sclerenchyma near the periphery of the culm, 
show a marked relation to lodging. As an index the above characters 
fail to indicate with any degree of accuracy which are the nonlodging 
forms. The evidence points to the possibility of quality rather than 
quantity of strengthening tissue as the important factor in determin- 
ing which forms will stand up. 

What has been mentioned about the 6-rowed barleys likewise ap- 
plies to the 2-rowed sorts. No morphological character which may 
be used as an index to lodging is apparent from the data presented. 

From an examination of the oat sorts for which there are three 
years' data on lodging, it is apparent (Table 3) that strain I-15-40, 
which is a large Garton variety, contains more bundles and a larger 
area both of sclerenchyma and bundles than the other two strains, 
Department No. 5168 and Swedish Select. However, when the 
average culm diameter of I-15-40 is taken into consideration the 
significance of the differences just mentioned becomes questionable, 
particularly in view of the fact that strain I-06-28, Department No. 
5168, altho possessing a stiff er straw than strain I-15-99, Swedish 
Select, has a somewhat smaller number of bundles, less sclerenchyma, 
and less bundle area. It should be noted that Department No. 5168 
is a short, low-yielding strain which matures somewhat earlier than 
the other two varieties. More data are needed to answer this ques- 
tion satisfactorily. Oat sorts I-i 7-72, I-17-40, and I-17-70, for 
which there are but one year's data on lodging available, show prac- 
tically no correlations between lodging and the above characters. 
The first and last strains are Sixty-Day selections and I-17-40 is a 
selection made from S. P. 1. No. 33644, also an early oat. In the 
plant rows I-i 7-72 was noticeable because of its stiff straw when 
other forms, such as I-17-70, lodged very badly. It may be of in- 
terest to point out here that of these two Sixty-Day selections the 



GARBER & OLSON : LODGING IN CEREALS. 



179 



one with the stiffer straw possesses thicker walled sclerenchyma cells 
(see Plate 6, figure 2). No. 1-17-72 also has the thicker culm wall. 



Table 3. — Average data recorded on culm measurements of oats, wheat, and 

rye. 



Field material measured at bottom 
internode.a 



Greenhouse material measured at 5th 
internode. 



Nursery 


. 

C :/> 






j„- 









jn 





J, 









selection 


n bio 






»i — 


. 




c . 






s = 


c . 




c . 


No. 


C 




% £ 


S 

c ^ 


u " 

V J; 




S S E 


a; 3 


i/i 

E 


c ? 




cs -3 


2 E 




Oi, 


Num 
indivi 


Diam 
1 cul 


Thick 
1 culm 


U 


_ c 

C3 3 




Num 
indivi 


Diam 
cul 


Thick 
culm 


11 


Total 
bun 




Oats: 






mm. 


mm. 




sq.mm. 


sq.mm. 




mm. 


mm. 




sq.mm. 


sq.mm. 


I-15-40 


I 




5-132 


0.567 44-42 


0.704 


1.207 


19 


4.437 0.879 42.16 


0.509 


0.879 


1-06-28 


2 














24 


2.979! .684 25.00 


.332 


.533 


I- 1 5-99 


3 


14 


4364 


-479 33-86 


•536 


.878 


16 


3-463 


.749 


26.19 


.348 


.662 


I-17-72 


I 














21 :3-i43 


.712 


25-38 


•337 


•563 


I-17-40 
















18 


3-350 


.614 


34-89 


.388 


•539 


I-17-70" 


3 


18 


3250 


-345 


20.89 


.277 


-503 


21 


3.200 


.514 


26.62 


.316 


-514 


Winter 




























wheat : 




























I-01-3 


I 














8 


2.688 


.318 


24-38 


.266 


.415 


1-03-68 


2 














9 


2.744 


.512 


28.00 


.301 


-572 


Winter rye 
















lO*^ 


3.870 


.3x6 


29.80 


.366 


-948 


Spring 




























wheat : 




























11-06-39^ 


I 


19 


3-6i6 


•451 


28.47 


•355 


.605 














Check'' 


2 


14 


3.007 


.504 


26.93 


-315 


-592 















a Strain No. 1-17-70 measured at third internode, the other oats at the fourth 
internode. 

^ Measured at third internode. 
Measured at fourth internode. 

As winter wheat and spring wheat are each represented by but two 
sorts, trustworthy conclusions cannot be drawn from so few data. 
However, the evidence does show the more nonlodging form of spring 
wheat to have a slightly larger number of vascular bundles, greater 
average area of sclerenchyma, and a somewhat greater average total 
area of bundles. In the case of winter wheat these conditions are 
just reversed. Of the two winter wheats, Odessa and Turkey, the 
former has a stiff straw, while the latter lodges badly. 

Winter rye, the least lodging form, shows a higher proportion of 
sclerenchyma area to average area of bundles^ than any of the cereal 
strains studied. Considering only the greenhouse material the abso- 
lute average area of sclerenchyma of the rye ranks second, barley 
strain II-16-131, a 2-rowed sort, being the only one to surpass it in 
this respect. The large sclerenchyma area of the latter loses some 



l80 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



of its significance when size of culm is taken into consideration. 
Selection II-16-131 possesses the largest clum of all the material 
grown in the greenhouse. 

RELATION OF DIAMETER OF CULM TO NUMBER OF VASCULAR BUNDLES. 

In general the cereals studied show no consistent correlation either 
between lodging and number of bundles or between lodging and 
diameter of culms. In order to determine whether there was some 
relation between diameter of culm and number of bundles for the 
different varieties, graphs were prepared. It would be reasonable to 
expect culms with a large diameter to contain more bundles than 
those with smaller diameters. This was found to be the case. 



25 



Aver^^e Number or 3und/es 
30 35 



40 



45 



5.0 



1" 

I 



I 3.5 



3.0 











































































































V 














































































































\ 






































































































y 










































































































t 






























































































































































r 


































A 




















































' 
















































































































\ 








































































































7 






























































\ 




/- 




































% 
















\ 



















































































































































































































































Fig. 13. Frequency graphs showing relation between diameter of culms 
and number of vascular bundles in oats. Measurements of greenhouse mate- 
rial were taken at the fifth internode, and those of field material at the fourth 
internode. 



The graphs (figure 13) show the relation between average diameter 
of culm and average number of bundles for the different oat varie- 



GARF.ER & OLSON I LODGING IN CEREALS. 



I8l 



ties studied. The field-grown material shows an especially high cor- 
relation between these two characters. With culms of large average 
diameters there is associated a large number of bundles. This con- 
dition is, perhaps, to be expected because from a purely physical 
standpoint the varieties with a large culm diameter and hence con- 
siderable culm wall have more tissue in which bundles may develop 
than those varieties which have less culm wall. The oats grown in 
the greenhouse, likewise, show correlation between diameter of culm 
and number of vascular bundles. Here there is more fluctuation, as 
is brought out by the graph, but still a strong correlation is evident. 

The graphs (figure 14) of the relation between mean culm di- 
ameters and mean number of bundles for the different varieties of 
barley show, both in the material grown in the greenhouse and that 
grown in the field, considerable irregularity. Even tho the graphs 
fluctuate a great deal, they show a distinct correlation between these 
two characters. 

From the foregoing observations it seems that among different 
varieties, diameter of culm is the most important factor in determin- 
ing the number of vascular bundles. 

RELATION OF LENGTH OF LIGNIFIED CELLS TO LODGING. 

As has been stated, a maceration study was made to determine if 
there was a significant difference between length of lignified cells 
found in the lodging and nonlodging strains. From the data pre- 
sented in Table 4, it is evident that there are no striking differences 
between the various strains of the same kind of cereal and small 
differences even between the- different kinds. There is an indication 
that winter wheat possesses longer lignified cells than the other 
cereals. 

Taking into consideration the spread of the frequency distributions 
the difference betvv^een the means is small. The extreme difference 
between the various strains of barley is only 1.81 units. A significant 
difference f4x the P. E.) based on 105 measurements of barley sort 
I-16-8 is about 1.8; thus it is seen that this standard gives but two 
differences which are barely significant among the barleys. Grant- 
ing that these differences are real, it is evident that they possess no 
value as an index to lodging. The barley strains ranking one and 
two as nonlodgers likewise represent the longest and shortest strains, 
respectively. Similarly, the other possibly significant difference is 
found between the two sorts which lodge most. 

The oats, rye, and w^inter wheat likewise show an inconsistent rela- 
tion between length of lignified cells and lodging. 



1 82 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 4. — Frequency distribution study of length of lignified cells in oats and 
barley grown in the greenhouse (measurements at fifth internode) 



Nursery 
selection No. 


Variety. 


Rank 
as non- 
lod .' ers 


7 


10 


13 


16 


10 


22 


25 


28 31 


34 


Total. 


Aver- 
ages.* 


Barley: 




























II-16-116 


Manchuria X Svanhals 


I 


I 


4 


10 


18 


II 


5 


I 






50 


16.24 


II-16-77 


S. African X Manchuria 


2 


2 


II 


31 


17 


7 


6 


I 






75 


14-43 


I-16-15 


Servian 


3 




5 


22 


6 


9 


4 


2 


I I 




50 


16.02 


II-16-78 


Bohemia X Manchuria 


4 


I 


5 


18 


13 


8 


3 


2 






50 


15.20 


I-16-60 


Chicago No. 63 


5 


I 


8 


II 


13 


10 


5 


2 






50 


15-56 


I- I 6-33 


Lake City 


6 


I 


6 


12 


17 


7 


6 


I 






50 


15.84 


I-16— 14 


Trebi 


7 




6 


15 


18 


7 


2 


2 






50 


15-38 


I- I 6-8 


Featherston 


10 


4 


20 


24 


33 


13 


4 


4 


3 




105 


15.10 


I- I 6-45 


Scotch 20816 


12 


I 


7 


14 


16 


7 


5 








50 


15.24 


II-16-131 


Svanhals X 2r/6r 


13 


I 


10 


13 


8 


7 


7 


2 


I 


I 


50 


16.14 


I- 1 6-2 


Featherston 


14 


2 


10 


17 


12 


5 


3 


I 






50 


14.44 


Oats: 




























I-15-40 


Garton 


I 




6 


10 


19 


II 


4 








50 


16.18 


1— U0~20 


uept. ino. 5100 






5 


13 


15 


1 


4 


I 


I I 




50 




I-I5-99 


Swedish Select 


3 




5 


12 


22 


7 


3 


I 






50 


15.92 


I-I7-72 


Sixty- Day 






10 


13 


II 


8 


7 


I 






50 


15.40 


I-I7-4O 


S. P. I. No. 33644 • • • ■ 






7 


8. 


12 


9 


9 


5 






50 


17.26 


I-I7-7O 




3' 




6 


10 


14 


II 


4 


3 


2 




50 


16.90 


Winter rye 








I 


18 


IS 


5 


5 


5 


I 




50 


16.54 


Winter 




























wheat : 




























I-01-3 


Odessa 


I 




2 


9 


14 


7 


4 


8 


I 3 


2 


50 


19.36 


1-03-68 


Turkey Cosgrove 


2 




6 


II 


5 


8 


9 


4 


I 4 


2 


50 


18.90 



« The class unit is 0.0172 mm. 

& Averages computed directly from measurements. 

c Rank for 1918 only. 



RELATION OF THICKNESS OF LIGNIFIED CELL WALLS TO LODGING. 

While measurements were being taken on oat strains I-17-72 and 
I-17-70 a difference was observed in the thickness of their lignified 
cell walls, as has already been mentioned. With the aim of de- 
termining this difference a number of measurements were made 
under an oil immersion lens. The data collected on this character of 
oats are shown in Table 5 and of barley in Table 6. 

All measurements were made from cell cavity to cell cavity and 
really included a double cell wall. Ten sections of each of the early 
oats were examined as to the thickness of the lignified cell walls found 
near the periphery of the culm and those surrounding the vascular 
bundles. Ten cell walls selected at random in each of these two 
areas of a section were carefully measured, thus making 100 read- 
ings for each strain. The other strains of oats and all of the barleys 
are represented by 50 readings each. 

Unfortunately the thickness of the sections studied made it im- 



GARBER & OLSON: LODGING IN CEREALS. 1 83 

possible to focus sharply under an oil immersion lens. However, it 
is felt that the measurements are sufficiently accurate for the present 
purpose. 

Avena^e Number of Dundles 
30 35 40 45 50 




Fig. 14. Frequency distribution graphs showing relation between diameter 
of culms and number of vascular bundles in barley. Measurements of green- 
house material were made at the fifth internode, and those of field material at 
the fourth internode. 



Considering the early oats (Table 5) alone in one group and the 
remaining three sorts in another group, it is evident that there is a 
positive correlation between nonlodging and thickness of scler- 
enchyma cell wall. This character shows a significant measurable 
difiference, with two possible exceptions, between any two strains in 
favor of the more nonlodging sort. The difiference between the cell 
walls surrounding the bundles of strains I-06-28 and I-15-99 re- 
spectively is 0.1 16 ±: .058, which is only two times its probable error. 
The difiference in thickness of cell walls in the sclerenchyma near 
the outside of the stem between strains I-15-40 and I-06-28 is also 
rather small (0.160 it .066) in view of its probable error. 

In order to corroborate the above results more sections of the ori- 
ginal material of sorts I-17-72 and I-17-70, both of which are selec- 



184 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



tions from commercial Sixty-Day oats, were prepared by using a 
slightly modified technic from what was previously employed. Meas- 
urements were taken as before under an oil immersion lens. Again 
significant differences between the thickness of sclerenchyma cell 
walls in favor of the more nonlodging sort was obtained. Lignified 
cell walls near the outside of culms showed a difTerence of 1.055 — 
.075, while those which surrounded the bundles showed a dif¥erence 
of 0.480 ± .048. 

Differences in thickness of lignified cell walls between sorts I-i 7-72 
and I-17-70 are also brought out in Plate 6, figure 2. 

From the evidence presented it is reasonable to expect that in oats 
the character, thickness of sclerenchyma cell wall, may facilitate 
the immediate segregation of the more nonlodging forms. Further 
evidence on this point is being sought. 



Table 5. — Thickness of lignified cell walls of oats grown in the greenhouse. 
{Data are averages of ten readings taken at the fifth internode.)^ 





Sclerenchyma near 


periphery of stem. 


Sclerenchyma around bundles. 




Early oats. 


Medium oats. 


Early oats. 


Medium oats. 










6 


06 


C> 




6 




6 




OS 






i 


f 




M 


f' 












T 




1 











VO 












ID 




2.75 


2.03 


1.25 


2.63 


2.75 


2.38 


2.25 


1.40 


1.25 


2.28 


2.10 


1.83 




2.58 


1.90 


1. 10 


2.40 


2.23 


2.10 


1.80 


1.50 


1-30 


2.15 


1.90 


1.68 




2.30 


1.90 


I-I5 


2.45 


2.30 


1.78 


1.80 


1.40 


1.25 


2.20 


1.98 


1.60 




2.05 


1-93 


1.23 


2.60 


2.03 


1.88 


1.85 


1.60 


1.05 


2.20 


1.48 


1-95 




2.30 


1.83 


I. GO 


2.48 


2.45 


1.88 


1.90 


1.65 


•95 


1.90 


1.88 


1.70 




2.60 


1.88 


1.08 








1.70 


1.50 


1. 10 










3-25 


1-73 


1.08 








2.50 


1.50 


1.20 










3-33 


1.68 


1.50 








2.15 


1-45 


1. 00 










3-30 


2.08 


1-55 








2.20 


1.50 


1. 10 










3-08 


1.78 


1.48 








2.30 


1.50 


I-I5 








Total 


27-54 


18.74 


12.42 


12.56 


11.76 


10.02 


20.45 


15.00 


11-35 


10.73 


9.34 


8.76 


Average . . . 


2.754 


1.874 


1.242 


2.512 


2.352 


2.004 


2.045 


1.50 


I-I35 


2.146 


1.868 


1-752 


P. E. of 


























averages. . 


.046 


•032 


.026 


.048 


.046 


•043 


.022 


.023 


.027 


.047 


.047 


-034 



« The unit is 0.00155 mm. 



Similarly, measurements were taken on the barley strains, but with 
different results, as may be seen by examining Table 6. Neither the 
thickness of the lignified cell walls found near the periphery nor those 
near the bundles show a consistent correlation with the relative ability 
of the sort to stand up. Thickness of cell walls in the sclerenchyma 



GARBER & OLSON ! LODGING IN CEREALS. 



185 



of barley shows much fluctuation. A difiference of only o.iio in this 
character was found in the sclerenchyma near the outside of the culm 
between the average of the strains ranking 2 to 9 inclusive as to 
nonlodgers and 10 to 15 inclusive. These same two groups dif¥ered 
by 0.078 with respect to thickness of lignified cell walls surrounding 
the bundle. The comparatively small differences, together with the 
fluctuations already mentioned, made it impossible to pick out with 
any degree of certainty the nonlodging strains of barley. It is barely 
possible that thinner sections which could be measured more accu- 
rately under an oil immersion lens would reveal differences similar 
to the oats, but in a much less degree. 



Table 6. — Thickness of lignified cell walls of barley grown in the greenhouse. 
(Data are averages of ten readings taken at the fifth internode.)^ 

SCLERENCHYMA NEAR. PERIPHERY OF STEM. 







in 


CO 


6 














m 






Selection 
numbers. 




i 




1 


cn 

T 






00 
T 






vo 


1 




Rank as 




























non-lodgers 


2 


3 


4 


5 


6 


7 


9 


10 


II 


12 


13 


14 


15 




2.45 


2.05 


1.63 


1-75 


1.20 


2.58 


1.80 


1.85 


2.50 


2.35 


1.33 


1.78 


1.90 




2.13 


1.75 


1.95 


1.85 


1.68 


2.33 


2.23 


1.60 


2.40 


2.45 


1.35 


1.83 


2.00 




2.65 


2.05 


1.78 


1.98 


2.08 


.2.53 


2.23 


1-93 


2.23 


2.55 


1.20 


1-93 


1.70 




1.85 


2.75 


1.48 


2.10 


1-45 


2.25 


2.20 


1.50 


1.90 


2.50 


1. 15 


1.83 


1.98 




1.80 


2.45 


1.25 


1.60 


1.20 


2.38 


2.10 


1-95 


1-43 


2.48 


1.25 


1.75 


1.70 


Total 


10.88 


11.05 


8.09 


9.28 


7.61 


12.07 


10.56 


8.83 


10.46 


12.33 


6.28 


9.12 


9.28 


Average . . . 


2.175 


2,21 


I.6I8 


..856 


1.522 


2.414 


2. 112 


1.766 


2.092 


2.466 


1.256 


1.824 


1.856 



SCLERENCHYMA AROUND BUNDLES. 





1.60 


1.25 


1.30 


1-33 


I 


20 


1.58 


1.43 


X..5 


1.50 


1.25 


1.20 


1-33 


1.23 




1.70 


1. 10 


1.20 


1.23 


I 


•25 


1.70 


1.40 


1.23 


1.28 


1.40 


I.I3 


1.35 


1.23 




1.60 


1.15 


1.40 


1. 18 


I 


20 


1-43 


1.30 


1.20 


1-35 


1-35 


1. 18 


1.20 


1. 13 




1.58 


1-45 


1.23 


1-53 


I 


•15 


1-53 


1.40 


1. 13 


1.33 


1.40 


1.25 


1.25 


1.20 




1.38 


1.20 


I-I5 


1.23 


I 


•05 


1-43 


1.23 


1.30 


1.23 


1-45 


1.28 


1. 13 


1.28 


Total 


7.86 


6.15 


6.28 


6.50 


5 


85 


7.67 


6.76 


6. II 


6.69 


6.85 


6.04 


6.26 


6.07 


Average . . . 


1.572 


1.23 


1.256 


1.30 


I 


.17 


1.534 


1.352 


1.222 


1.338 


1.37 


1.208 


1.252 


1. 214 



a The unit is 0.00155 mm. 



CONCLUSIONS. 

Extreme varieties for lodging in wheat, oats, and barley, were 
selected for this study, and measurements were also made of Minne- 



1 86 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

sota No. 2 winter rye, which stands up better than the other cereals. 
A study was made of the correlation between lodging behavior and 
average size of culm, average number of bundles, average area of 
sclerenchyma, thickness of culm wall, length of lignified cells, and 
thickness of lignified cell wall. None of the above-mentioned char- 
acters except thickness of cell wall seems closely related to lodging. 

Both the early and medium oat strains examined showed a distinct 
correlation between thickness of lignified cell walls and lodging. 

In general, lodging in cereals is dependent on so many factors of 
unequal value in the different sorts that no one factor seems to be 
correlated closely enough with lodging to be of much value as a 
selection index. 

Among the different strains of oats and barley, average number of 
vascular bundles was found to be correlated with average diameter 
of culms. 



Journal of the American Society of Agronomy. Plate 6 




Fig. I. Cross-section of barley strain T-16-2, showing some of the measure- 
ments taken. The defects which appear like air bubbles were due to globules 
of celloidon which were not entirely removed by the ether treatment. 




Fig. 2. At the left, cross-section of oat strain I-17-70, a lodging form of 
Sixty-Day. At the right, cross-section of oat strain I-17-72, a non-lodging 
form of Sixty-Day. Note the thicker walled cells of the sclerenchyma tissue 
Ijoth near the periphery of the stem and around the 1)und]c as compared with 
I-17-70. 



VVALDROX & CLARK : RUST-RESISTING WHEAT. 



187 



KOTA, A RUST-RESISTING VARIETY OF COMMON 
SPRING WHEAT/ 

L. R. Waldron and J. A. Clark. 

Resistance to stem rust of wheat (Piiccinia graminis tritici) is a 
quality lacking among the varieties of common spring wheat now 
grown commercially in the hard spring wheat sections of the United 
States. Following the introduction of the Marquis variety, claims 
were made for its rust resistance, but further tests showed that it 
merely escaped rust. 

True resistance, however, has long been recognized in many varie- 
ties of durum wheat. The introduction of the durum wheats, and 
later of the Marquis, into the hard red spring wheat region were epoch- 
making events. These wheats won their way almost entirely because 
of their increased yield over the varieties already in cultivation, the 
increase being due in large measure to the relation of the wheats to 
stem rust. The durums were resistant and the Marquis evaded rust 
by ripening early. 

In an endeavor to originate a rust-resistant variety of common 
spring wheat, resistant varieties of durum wheat have been crossed 
with commercial varieties of common wheat. This, apparently, 
afforded the most practical means of obtaining the desired end. Re- 
sults up to the present, however, have not been very successful. No 
high-yielding hybrid of common wheat having the rust resistance of 
the durum and the good milling and baking qualities of Marquis has 
yet been originated. 

The authors believe that the Kota, the variety of common wheat 
here discussed, possesses the rust resistance sought. It also gives 
promise of being a high yielding and an excellent bread-making wheat. 
If the variety does not in itself possess all of these quahties, it is 
hoped that its discovery will obviate the necessity for further cross- 
ing durum and common wheats in breeding for rust resistance. 

History. 

Kota wheat first came to the attention of the authors in 191 1, when 
they were located at the Dickinson Substation, Dickinson, N. Dak. 

^ Joint contribution from the North Dakota Agricultural Experiment Sta- 
tion, Agricultural College, N, Dak., and the Bureau of Plant Industry, United 
States Department of Agriculture, Washington, D. C Received for publica- 
tion April 4, 1919. 



1 88 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



The station that year received from Prof. H. L. BoUey, biologist of 
the North Dakota Agricultural College, samples of four durum 
wheats designated by him as D-i, D^4, D-5, and D-7. These were 
first grown in 191 1 and because of high yield the D-i was continued 
in the experiments at Dickinson. It was given the name of Monad 
by Ball and Clark^ in 1918. The Monad is one of 25 lots of wheat 
introduced from Russia in November, 1903, by Professor BoUey, who 
in that year made a study of the flax industry in Europe for the 
United States Department of Agriculture. These varieties were in- 
troduced as Foreign Seed and Plant Introduction Nos. 10194 to 10218. 

When introduced at Dickinson the Monad contained an admixture 
of about 25 percent of a bearded common spring wheat, as evidenced 
by a sample of the 1911 crop on storage at the experimental mill. 
As no intensive work was undertaken with the Monad wheat at that 
time no attempt was made to purify it, other than the annual rogue- 
ing of the plots. In the rust epidemic of 1916, the Monad variety 
proved to be extremely rust resistant. It yielded at the rate of 26.2 
bushels per acre, or 8.8 bushels more than the next highest yielding 
durum variety, and 12.7 bushels per acre more than Marquis. In 
studying head samples from this plot after harvest the authors dis- 
covered independently that the common wheat which was still mixed 
with it also showed evidence of rust resistance. As a result of these 
observations, separations of the common wheat were made in 191 7 
and to these the name Kota has now been applied. The name is 
a shortening of the latter part of the State name, North Dakota. It 
has been given Cereal Investigations No. 5878 by the Office of Cereal 
Investigations of the United States Department of Agriculture and 
No. 10003 by the North Dakota Agricultural Experiment Station. 

This wheat may have been one of Professor BoUey's original intro- 
ductions, but it is now impossible to associate it with its proper Seed 
and Plant Introduction numbers. It is very similar in appearance, 
however, to his R. B. R. 3. 

Description. 

The description of the Kota variety is as follows : 

Plant spring habit, midseason, midtall ; straw white, strong; peduncle 
straight, hollow; spike awned, fusiform, middense (40 to 55 mm. per 10 
nodes); glumes glabrous, white, midlong, midwide ; shoulders midwide, square 
to elevated ; beaks narrow, 3-20 mm. long ; awns white, 5-8 cm. long ; kernels 
dull red, midsized, ovate, slightly humped; germ area small; crease wide, 
usually shallow; cheeks usually rounding, brush short. 

2 Ball, Carleton R., and Clark, J. Allen. Experiments with durum wheat. 
U. S. Dept. Agr. Bui. 618, p. 44. 1918. 



WALDROX & CLARK: RUST-RESISTING WHEAT. I 89 

Among the pure lines selected there are some slight variations in 
kernel type. About 30 percent of the selections have slightly longer 
and narrower kernels, which somewhat resemble those of the Crimean 
group of hard red winter wheats. At least one of the selections has 
soft kernels and several have distinctly angular cheeks. There is 
little variation in the spike characters among the different pure lines. 
The variety can be distinguished from Preston (''Velvet Chaff"), 
the variety it most closely resembles, by longer beaks on the outer 
glumes and by the distinctly elevated shoulder (see Plate 7, figure i). 
Two strains of Preston were among the original separations made, 
but they were easily recognized by these characters and their sus- 
ceptibility to rust. 

Yield. 

Yield data have been obtained in only one season, 1918, and at one 
place, Fargo, N. Dak., and only for the mass variety. Meager as 
these results are, it seems desirable to present them. 

A number of wheat varieties were sown in 17- foot rows, replicated 
five times. The yield and rust data recorded are given in Table i. 



Table i. — Acre yield in bushels of 17 varieties of spring wheat grown at the 
North Dakota Agricultural Experiment Station, Fargo, N. Dak., in 1918, 
with percentage of stem-rust infection on each. 



Class and variety. 


C. I. 

No. 


\ ield per acre. 


Rust 
infection. 


Class and variety. 


C. I. 

No 


Yield per acre. 


Rust 
infection. 






Bushels. 


Percent. 






Bushels. 


Percent. 


Durum : 








Common, con'd: 








Monad .... 


3320 


35.96^0.64 


5 


Power Fife, N. 








Mindum . . . 


5296 


34-48^1.41 


10-15 


Dak. No. 920 




25-55^ -91 


65 


Kubanka . . 


4063 


33.oo±i.2i 


25 


Red Fife 


3329 


24.71=*= .74 


65 


"D-5" .... 


3322 


3i.6i±i.44 


0- 5 


Power Fife . . . 


3697 


23.28=1=1.11 


65 


Arnautka . . 


1494 


29.28 =t .71 


25 


Red Bobs 




20.41 ± .53 


65 


Buford 


5295 


27.21 ±1.68 


15-20 


Preston 


3328 


i9.97='=i.oo 


65 


Common : 








Ghirka Spring 


1517 


19.85 ± .44 


65 


Kota 


5878 


29-53^ -74 


10-15 


Haynes Blue- 








Marquis . . . 


3641 


29 33^ -90 


25 


stem 


3020 


19.52^1.31 


65 


Kitchener . . 


4800 


26.90± i.oi 


65 


Ruby 


6047 


i8.70=t: .91 


25-40 



The six durum varieties (Table i) show an average yield of 31.92 
bushels per acre, while the 10 common wheats, not including Kota, 
averaged but 22.82 bushels per acre. The Kota wheat yielded 29.53 
bushels, slightly less than the average for the durums. Marquis 
yielded 29.33 bushels, practically the same as Kota. The durum 
yields varied considerably, ranging from 27 bushels for Buford to 
36 bushels for Monad. 



190 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Comparative yields were secured also from larger plots of several 
varieties. The grain was sown with a garden drill in rows i foot 
apart. The plots were of various sizes, most of them being larger 
than a hundredth acre. The following tabulation gives the results : 

Group or variety. No. of plots. Yield, bushels per acre. 

Durum 7 31.62 + 1.17 

Power and Red Fife 5 21.74 +1.00 

Marquis 3 21.48 + 1.12 

Bluestem 2 20.38 ± .77 

Preston i 18.15 

Kota I 28.40 

Here again, the durums outyielded the other wheats, but the 
Marquis yielded less than Power of Red Fife. The yield of Kota 
is decidedly higher than any of the other hard red spring wheats and 
is only 3 bushels below the durum yields. No rust notes were taken 
on these wheats. 



Rust Resistance, 
data from nursery experiments. 
In 19 1 7 the senior author selected 48 heads of the common wheat 
from the Monad variety grown at Fargo, N. Dak., in addition to the 
composite sample used in the experiments just discussed. The seeds 
from these were grown in head rows at Fargo in 1918. Two of these 
selections proved to be Preston, so there were only 46 head rows of 
Kota. 

The junior author also made head selections of the common wdieat 
from the Monad variety grown at the Judith Basin Substation, 
Moccasin, Mont., in 1917. Ten of these selections were sent to the 
experiment stations at Brookings and Highmore, S. Dak., and Man- 
hattan, Kans., and twenty to University Farm, St. Paul, Minn. The 
results of these preliminary trials have revealed rust resistance far in 
excess of that of other common spring wheats. 

At Fargo, N. Dak., the 46 pure lines of Kota had stem-rust infec- 
tion varying from 5 to 15 percent. The percentages of rust infec- 
tion on the 46 head rows were distributed in groups as follows : 

Stem-rust infection in percentage groups — 5 5 5-10 10 10-15 

Number of head rows in each group 4 18 16 4 4 

The mean rust infection for these Kota strains is 6.74 percent. 
The two head rows of the Preston type showed rust infection of 45 
and 65 percent, respectively, while two adjacent head rows of durum 



VVALDRON & CLARK: RUST-RESISTING WHEAT. 



191 



wheat showed 5 and 40 percent. Several rows of Power Fife, sown 
in a depression in the plot, showed 40 to 65 percent of infection. 

The mean rust infection on 6 varieties of durum wheat, as shown 
in Table i, is 14.6 percent, the infection ranging from less than 5 
percent in the red durum, " D-5," to 25 percent in Kubanka and 
Arnautka. The ]\Iarquis and Ruby wheats, notwithstanding their 
early maturity, showed 25 percent or more of rust infection. The 
other wheats, except the Kota, were heavily infected. The mass- 
selected Kota was recorded as having from 10 to 15 percent of rust. 

At Brookings, S. Dak., the ten pure lines of the Kota showed rust 
infection of 20 percent, compared with 40 to 65 percent infection on 
other common wheats, and as low as 10 percent on the most resistant 
durums. 

At St. Paul, Minn., eight pure lines grown in the cereal rust 
nursery. Six had rust infections of 15 percent. Two proved suscep- 
tilbe to rust, both having an infection of 80 percent. In the same 
nursery, durum wheats were infected from i to 70 percent, and 
common w^heats from 70 to 100 percent. In this nursery a rust epi- 
demic was artificially produced. The nursery included 820 varie- 
ties and strains of domestic and foreign origin. The six resistant 
strains above mentioned, together with two apparently identical 
strains selected by Mr. John H. Parker, were more resistant than any 
other common spring wheats, except three unadapted foreign varie- 
ties. In the agronomy breeding nursery, with only natural rust in- 
fection, five pure lines of Kota had infections ranging from o to 10 
percent. 

At Highmore, S. Dak., and at Manhattan, Kans., where ten pure 
lines of the Kota were grown, absence of rust prevented the making 
of any comparisons. 

The data recorded on 67 out of 69 pure lines show that the Kota 
was much more resistant to the attacks of the form or forms of 
wheat stem rust present in 1918 at Fargo, N. Dak., Brookings, S. 
Dak., and St. Paul, ^linn., than were the other hard red spring 
wheats. The percentage of infection was only slightly greater than 
the average for the durum varieties. 

It will be noted that the Monad variety, from which Kota was 
separated, is resistant, but is exceeded in this respect by the red- 
kerneled durum wheat, "D-5." The suggestion has been made that 
Kota wheat may have originated from a natural field hybrid between 
a common v.'heat and Monad (D-i), D-5, or some other durum 
wheat. Accurate knowledge of the histology and morphology of such 



192 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



hybrid forms is very meager. A close study of Kota wheat, with a 
more extended study of known hybrids, ought to lead to definite 
conclusions. 

DATA FROM GREENHOUSE INOCULATION EXPERIMENTS. 

Dr. E. C. Stakman, collaborating pathologist at the Minnesota 
Agricutural Experiment Station, has conducted rust inoculations on 
the bulk Kota wheat and the Monad durum, which field observations 
in North Dakota have shown to be a rust-resistant wheat. He has 
very kindly furnished us these data in advance of publication. In 
cooperatiove experiments with the Ofiice of Cereal Investigations, 
Doctor Stakman and his coworkers^ have isolated different biologic 
forms of Pnccinia grarninis tritici. It has been found that these 
forms have chfferent geographic distributions, within certain limits. 
The data presented include results of rust inoculations from rust 
spores collected in various parts of the United States. Different 
biologic forms undoubtedly are represented in the list, but certain 
forms no doubt are duplicated. The data are presented in Table 2. 
The scale of infection is as follows : 

0. No infection. 

1. Minute uredinia with some hypersensitiveness. 

2. Moderate uredinia with some hypersensitiveness. 

3. Moderate uredinia and no hypersensitiveness. 

4. Heavy normal infection. 

The plus, minus, double plus and double minus indicate inter- 
mediate degrees. 

The degree of correlation existing between the results obtained in 
the greenhouse and the natural infection taking place in the field, using 
the same hosts and the same forms of the parasite, is yet unknown. 
A study of the results shows considerable variation in the amount of 
infection on the Kota and less variation on the Monad. The amount 
of infection on the Kota, using the data where they are comparable, 
is distinctly less than on the Monad. The fact that the Kota reacts 
positively to rust collected at several points in Minnesota and North 
Dakota is puzzling, in view of its field behavior at Fargo, N. Dak. 
The natural assumption is that certain biologic forms of rust, to which 
Kota wheat is susceptible, exist in part of North Dakota, but have not 
been present at Fargo. Such a fact would be, a priori, somewhat 

3 Stakman, E. C, Levine, M. N., and Leach, J. G. New biologic forms of 
Puccinia grarninis. In Jour. Agr. Research, v. 16, no. 3, p. 103-105. 1919. 



WALDRON & CLARK: RUST-RESISTING WHEAT. 



surprising, considering the topography and rather uniform cHmatic 
conditions of the State. 



Table 2. — Degrees of rust infection obtained at University Farm, Minn., on 
Kota' and Monad wheat, using spores from various localities. 



Rust 
series 
No. 



66a 
66b 
96 

8a 

2 
30 

5 

136 
26 



Source of rust-spores. 



Degrees of 
stem-rust in- 
fection on — 



Kota. 



Monad. 



Rust I 

series Source of rusts pores. 
No. 



Ainsworth, Xebr.. . . 1 + 
do 4 

Alton, Iowa 

Baton Rouge, La. . . 3 = 

Brundidge, Ala o 

Clearspring, Minn. . . 

Corvallis, Oreg o 

Denver, Colo 

Fairmount, Nebr. . . 



3 + 

3 + + 
3 = 
4 

3 + 



39 Grand Forks, N. Dak 

37 ! Minneapolis, Minn,. 

65 I Oklee, Minn 

79 i Powers Lake, N. Dak 

129 i Presque Isle, Maine 

I ; St. Paul, Minn 

4 Stillwater, Okla 

143 Towanda, Kans 

17 I Valdosta, Ga 



Degrees of 
stem-rust in- 
fection on — 



Kota. Monad. 



3 - 
3 

3 + 
4- 

3 + 
3 + 
o? 
o? 



3 + 

3 

3 



3 

3 + 



Inoculation studies were made on several head rows of Kota wheat 
at ^lanhattan, Kans., during the winter of 1918-19 by Prof. L. E. 
]\Ielchers, who has kindly furnished some of the data in advance of 
publication. Professors ]\Ielchers found the Kota wheat to be sus- 
ceptible to P. graminis tritici inficiens Melchers & Parker.* This 
biologic form has been found to develop normally on seedlings grown 
in the greenhouse of the three hard red winter wheats, Kanred, 
P1066, and P1068, which are resistant to the rust form P. graminis 
tritici, as is Kota also. Aside from the difiference of spring and 
winter habit, the Kota and Kanred wheats seem to be closely allied 
morphologically. 

Professor Alelchers' general conclusions are as follows: 

The inoculations with Puccinia graminis tritici-inficiens were made in the 
seedling stage. Checks accompanied each series inoculated. Selections of 
Kota, when inoculated with Puccinia graminis tritici-inficiens, prove to be 
quite susceptible. Infection is usually heavy, uredinia numerous and generally 
from .5 mm. to 1.5 mm. in size. The only differences between this variety and 
any other susceptible variety of Triticum vulgare is the rather consistent pro- 
duction of medium to small uredinia. 



Milling and Baking Results. 

Samples of the bulk Kota wheat and of six other varieties grown 
at the North Dakota Agricultural Experiment Station have been 
milled and the flour baked in the milling and baking laboratory of the 

* Melchers, L. F., and Parker, John H. Another strain of Puccinia graminis. 
Kans. Agr. Expt. Sta. Cir. 68, 4 p. 1918. 



194 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Bureau of Markets, Washing-ton, D. C. The results obtained are 
given in Table 3. Photographs of a loaf of bread made from flour 
of Kota wheat and a series of loaves made from flour of each of the 
varieties milled are shown in Plate 7, figures 2 and 3. 



Table 3. — Milling and baking data on 7 varieties of wheat grown at the North 
Dakota Agricultural Experiment Station, Fargo, N. Dak., in igiSfi 



Variety. 


C. I. 
No. 


Lab. 
No. 


Bushel weight. 


Screen- 


Moisture content. 


Crude protein 
(NX5.7). 


Before 
clean- 
ing. 


After 
clean- 
ing. 


Wheat. 


Flour. 


ings. 


Before 
tem- 
pering. 


After 
tem- 
pering. 


Wheat. 


Flour. 












Per- 


Per- 


Per- 


Per- 


Per- 


Per- 








Lhs. 


Lhs. 


cent 


cent 


cent 


cent 


cent 


cent 


Marquis 


3641 


4790 


59.8 


60.3 


5-5 


II-5 


15-0 


12.5 


15-3 


14.2 


Kota 


5878 


4788 


61.0 


62.0 


2.8 


11.4 


15-0 


11.8 


13-8 


12.9 


Power Fife 


3697 


4789 


59-2 


60.5 


4.9 


11.4 


15-0 


12.5 


14-3 


13.2 


Preston 


3081 


4795 


60.5 


61.0 


5-2 


12.3 


15-0 


12. 1 


14.9 


13-6 


Haynes Bluestem 


2874 


4799 


57-0 


58.3 


2.9 


10.9 


15-0 


12.4 


15-3 


13-9 


Kubanka No. 8 


4063 


4797 


61.0 


60.3 


6.3 


ii-S 


15-0 


ii-S 


13 3 


12.8 


Monad 


332vO 


4791 


61. 1 


61.2 


3.6 


11.8 


15.0 


10.6 


12.8 


12.0 



Variety. 



Milling results. 



Flour. 



Marquis 

Kota 

Power Fife 

Preston 

Haynes Bluestem 

Kubanka No. 8 . . 
Monad 



Per- 
cent 



73-6 
69.4 
73-5 
71-5 
72.5 

72.8 
68.3 



I 

Bran. Shorts. L.oss. 



Per- 
cent 



15-5 
13-5 
14.0 
14.6 
15.6 

11.6 
14.2 



Per- \ Per- 
cent ! cent 



II-5 I 
15.6 
12.5 
II. 7 
10.8 

13.6 
14. 1 



.6^ 

1-5 

o 

2.2 
I.I 

2.0 
3-4 



Baking results. 



Ab- 

50 p- 

tion of 
water. 



Loaf. 



Vol- 
ume. 



I . , Tex 
; Weight. 



.-I 



Color. 



Score. 



Per- 
cent 



59-1 
63.2 
60.6 
59-7 
60.6 

59-1 
59-7 



2,950 
2,910 
2,590 
2,470 
2,330 



gm. 



482 
488 
487 
483 
493 



2,390 487 
2,210! 485 



Per- 
cent 



9I-S 

94- 5 
90.5 
90.0 
90.0 

96.5 

95- 5 



Per- 
cent 



95-5 
94.0 

91-5 
92.0 
91.0 

94.0 
90.0 



Shade. 



Slightly 
creamy 
gray 
do 
do 
do 
do 

creamy 
gray 
do 



<^ Data obtained by the Office of Cereal Investigations, Bureau of Plant In- 
dustry, in cooperation with the Bureau of Markets, United States Depart- 
ment of Agriculture. 

& Gain. 



The data show the Kota variety to be a good milling and an un- 
usually good bread wheat when compared with standard varieties. 
The wheat is comparatively high in weight per bushel, but somewhat 
low in yield of flour. The flour is high in absorption and the loaf 



Journal of the American Society of Agronomy. 



Plate 7. 




Fi(i. I. Head, glumes and kernels of Fic. 2. Loaf of bread baked from 

Kota wheat. 340 grams of flour of Kota wheat. 

Average volume of loaf, 2,910 c.c. 




Fig. 3. Seven loaves of bread from varieties of wheat grown at Fargo, 
N. Dak. The varieties, with the average loaf volume, are as follows (left to 
right) : Marquis, 2.950 c.c; Kota, 2,910 c.c; Power Fife, 2,590 c.c; Preston, 
2,470 c.c. ; Haynes Bluestem, 2.330 c.c. ; Kubanka No. 8, 2.390 c.c. ; Monad, 
2,210 c.c. 



WALDRON & CLARK: RUST-RESISTING WHEAT. 



ranks high in volume, weight, texture and color. The crude protein 
content is lower than in the other common wheats included in this 
experiment, but ranks far above the average for the class of common 
hard red spring wheats. The high weight per bushel and low yield 
of flour are similar to that found in Preston, which is a bearded 
common wheat. The large expansion shown by the loaf volume and 
the texture of the loaf, however, indicate that the variety is superior 
to Preston as a bread wheat, and also to Power Fife and Haynes 
Bluestem, and that it is equal to ^Marquis (see Plate 7, figures 2 and 3). 

The flour from the Kota wheat is granular, much like durum wheat 
flour, and is relatively low in volume compared with flour from 
other common wheats. In milling the wheat it was observed that 
it was about half way between common and durum wheat in hard- 
ness. The strength of the gluten revealed by the large loaf volume, 
however, does not indicate any similarity to durum wheat flour. 

Summary. 

A variety of bearded hard red spring wheat designated as Kota 
(C. L No. 5878) has been shown to possess resistance to the form or 
forms of the stem rust of wheat present at Fargo, N. Dak., Brook- 
ings. S. Dak., and St. Paul, Minn., in 1918. Additional evidence of 
such resistance was secured in 191 7. This resistance is decidedly 
greater than that possessed by the common spring wheats and second 
only to the more resistant durum wheats. 

Results secured at Fargo, N. Dak., in 1918 showed a capacity for 
yield decidedly above the average of the common wheats and only 
slightly less than the average yield of the durum wheats. 

Milling tests conducted with Kota wheat showed it to produce 
somewhat less flour than the average of other wheats used in the 
same test. Baking tests ranked it very high as a bread wheat, as it 
markedly exceeded the other common wheats except Marquis, which 
it equaled. 



196 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



OFFICIAL FIELD CROP INSPECTION.^ 

H. L. BOLLEY. 

Now, when it has been forcibly brought out that the nation is 
vitally interested in farm results and that to get maximum produc- 
tion some system of efficient supervision is essential, it may not be 
out of place to call attention to a line of work in which official super- 
vision would be beneficial and, for various reasons, quite essential, 
even under normal conditions. There is a phase of farm cropping, 
especially with cereals, in which the State is not only vitally inter- 
ested, but could become of great aid to growers and to the con- 
suming public. That line of work may perhaps be properly named 
official field crop inspection. 

Great strides have been made, from the educational standpoint, in 
crop improvement during the past 25 years. It is apparent, however, 
to those who are closest to the work that improvement in cereal 
cropping is not nearly proportionate to the general gain in informa- 
tion as to possible cropping methods. There is much knowledge as 
to tillage, crop rotation, and seed breeding, and much improvement 
in farm machinery and methods of crop handling thru farm ma- 
chinery ; yet the processes which, from a scientific standpoint, are 
necessary to high yield and quality are not in common practice and, 
when used, are so intermittently followed as to cause failure of crop 
improvement that should otherwise naturally follow. 

If the above is true, it is worth the attention of those of us who 
are specialists in certain lines of agriculture to try to determine the 
reasons for such failure to follow best processes and to arrive at a 
remedy along the lines which may result in g^etting the process con- 
structively carried on. 

For example, much work is done in breeding seeds. The States 
and Nation are at much expense to allow certain experts to study 
Mendelian methods of cross-breeding and other fines of work which 
result in the introduction of new varieties and kinds. Certain busi- 
ness men who are concerned with the results are not backward in 
saying that this introduction of varieties is often harmful rather than 

1 Contribution from the North Dakota Agricultural Experiment Station, 
Agricultural College, N. Dak. Read at the eleventh annual meeting of the 
American Society of Agronomy, Baltimore, Md., January 6, 1919, by Prof. J. 
H. Shepperd. 



BOLLEY : FIELD CROP INSPECTION. 



197 



beneficial and those of us who are close enough to the held to note 
the results are perhaps willing to admit that many valuable varieties 
are so intermixed and jumbled as to merit such disapproval. 

It is safe to say that, in cereal agriculture, varieties are not kept 
separate and are not handled in the same intelligent manner as that 
which characterizes the best fruit and vegetable growing methods. 
Is there any reason why this should be the case? 

Again, as I have pointed out in other addresses, most agriculturists 
and many able farmers are convinced that crop rotation is a neces- 
sarv process for best seed and crop production in cereals, yet there 
are few crop rotation series which are recognized for any particular 
region which are carried out w^ith any consistency. There must be 
some general reason which accounts for such failures to apply the 
principles, methods, and teachings which all of us and many able 
farmers believe in. 

I do not here wish to enter into a discussion of crop rotation, soil 
tillage, or purely sanitary matters of cropping, but will call atten- 
tion to one phase which I think illustrates the way out, so that 
processes known to be necessary may be constructively continuous. I 
advocate a legal basis for bringing about stability and standardiza- 
tion of varieties in cereal cropping. I believe that there is a good 
excuse for official supervision of seed production and distribution. 

I am not, I believe, unduly optimistic when I affirm that under 
properly systematized seed standardization and sanitary cropping 
thru means of proper handling of the soil and seed, any State or 
the Nation might readily lift its annual average yield of wheat several 
bushels per acre per year. I think that a minimum increase of 5 to 
10 bushels per acre for proper systematic handling of the seed crop 
might not be beyond reasonable expectation. Further, I believe this 
would be doubly assured w^ere it no longer possible for a man to plant 
the same general crop two years in succession on the same land. 
For the land control proposition we may not yet be ready, but cer- 
tainly for the seed control proposition we have reached the stage 
when it is folly to claim that further improvement can be made by 
simple processes of education when almost all the processes of 
marketing and general farm procedure are so conducted as to offset 
any improvement that can be made by intermittent educational 
processes, however effectively administered. I need only call atten- 
tion to the fact that there are very few new varieties of cereal which 
remain in reasonably pure form past the third generation on the farm 
an;i in the market. Very few of the wheats in the leading districts 



198 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

survive a decade before the)- are replaced by some new creation 
which runs perhaps only a shorter, more precarious existence. 

OPPOSITION TO PROGRESS. 

Many of us are prone to discant on the initiative being left in the 
hands of the farmer and many in the business world or manufactur- 
ing side are pretty sure to decry any attempt to improve matters by 
the enactment ,of law. I am cjuite convinced that laws which are 
enacted but never put into operation are useless. I am also convinced 
that those which are enacted and put into operation and which remain 
in operation, such as the sanitary laws for the control of Texas 
fever and smallpox and compulsory disinfection after diphtheria, 
scarlet fever, etc., are laws which should have been enacted and which, 
because they are still in force, prove that there was a necessity for 
such enactment. I believe that it will be understood that many 
laws are enacted which do not need to be enforced. They form the 
educational basis for stable processes. Many good laws are self 
operative. Such laws remain on the books as a basis and guide for 
those officials whose business it is to advocate progressive advance. 
Such a law, for instance, is the ordinary anti-expectoration law. It 
was easy to make fun of it and to say that it was unnecessary and 
that everything could be done by education, but who among us will 
contend that such criticism or opposition was well founded? 

Nevertheless, when we strike the matter of farming processes and 
indicate that there should be sanitary laws affecting farm processes, 
officially supervised by State officers not amenable to politics, there 
are many who object and say that such laws are unnecessary and that 
we should " rely on educational methods," indicating that too much 
supervision will bring about stagnation. Then there are others who 
are sure to call such laws sumptuary, tending to prevent individual 
freedom of action and toward depression of business operations. 

In years past we have gone so far in this laissez faire line of non- 
control of farming matters that any approach to supervision by the 
State of any farming work is sure to be resented by some lines of 
business, even tho it meets with favor in the eyes of those whom it is 
intended to help. Thus, for example, few of us but can remember 
the strenuous efforts to resist fertiHzer control lines of work, and the 
strong opposition to enactment of horticultural and entomological 
supervision for control of insect and fungous pests and to the enact- 
ment of simple seed inspection laws. Even now, in the work of 
plant-disease control, it is apparent that there are yet those who insist 



bolley: field crop inspection. 



199 



that the State should keep out, that there should be no supervisory 
laws effecting control work. When, for example, but lately it was 
proposed that the State and Nation should attempt control of wheat 
rust through barberry eradication, not a few who should know much 
as to the reasons for the necessity of such eradication spoke out 
freely and feelingly in the advocacy of a campaign of education, as 
tho we had not had that campaign for nigh on to two centuries. And 
now, if one should but propose compulsory seed treatment of cereals 
for prevention of smut and control of scab and similar cereal diseases, 
or a law simply to prevent continuous cropping of the land so that 
there might not be a continuous accumulation of such diseases in the 
soil and seed of special crops, many so-called educated men would 
throw up their hands in feigned horror. Yet enactment of such soil 
and seed laws would be but a natural consequence following upon 
years of investigation and established knowledge relative to what 
should be done in order to control such cereal diseases. In other 
words, it would be but a natural step toward carrying out present 
knowledge of cereal disease control through sanitary methods so 
that the work done may not be continually and perpetually a loss 
thru the carelessness of ordinary marketing and farming processes. 

I discuss this phase of the sanitary question as to soil and seed 
only to introduce the idea of the necessity that the States attempt by 
law to standardize seed quality thru proper methods of seed cropping 
and seed control. 

I propose the thought that many of our so-called educational cam- 
paigns need a basis of equitable law. One cannot expect sanitary or 
proper planning to be carried out merely on the suggestion of a 
professor from the agricultural college or of an extension worker if 
the carrying out of the processes must be placed eternally upon the 
Utopian basis that the man who does the work may hope for some 
results, but whether he does or does not get them he should be and 
is expected to do it so that his neighbor may also prosper. Merely 
to recite to him that the public should have the benefit of the better 
crop that he will raise loses force after a time except it be backed by 
an emergency such as has come about under war conditions. It is 
too great a strain on the word loyalty to ask it, unless asked of all. 
In fact, the work will not be done with sufficient unanimity to give 
worth-while results except it be done by all continuously, year by 
year. The proper basis for sanitation on the farm as to crops is not 
different than in the home, factory, and school. It should rest on 
equitable law, educationally and equitably administered. 



200 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

I believe that the first step in cereal crop improvement rests in a 
further extension of our State seed and weed laws and in the activity 
of the forces represented by them, to include proper control of seed 
crop production and of seed and grain distribution. 

PRESENT STATUS OF SEED PRODUCTION, CROPPING AND MARKETING OF CEREALS. 

In the line of cereal cropping and marketing we are not progress- 
ing as fast as the growth of our population calls for. The increase in 
population of the world, even in peace time, calls for a marked in- 
crease in cereal crop production. This increased demand has brought 
the total acreage of wheat in the United States, close to the maximum 
acreage at which labor is available for its production, and, what is 
worse, has reached such a high annual acreage in the chief regions of 
wheat culture that it is becoming extremely difficult to plan a rotation 
which will give sufficient improvement in the sanitary status of the 
soil as to allow of seed improvement. In spite of our knowledge in 
the matters of sanitary cereal cropping no consistent steps are taken 
to bring about such uniformity and continuity as may be likely to 
tend to improvement either in the seed quality used in bulk, from 
year to year, or in crop quality. 

These conditions result from (i) the failure of our educational 
campaigns to prevent the constant cropping of the soil to one crop or 
its close disease-infected cereal relations, and (2) the failure to hold 
varieties up to the standard of purity necessary to meet cropping and 
marketing needs. In the chief areas of cereal production, whether 
of wheat, oats, barley, or corn, constant cropping prevails as against 
constant processes of sanitary crop rotation. Particularly in wheat, 
barley, and oats cropping, the chief methods of production violate all 
the rules relative to standardized seeds more commonly than they are 
practiced. Here the large acreage producers and the elevators and 
process of marketing speedily undo all the ideas of crop sanitation 
and grain standardization. At least, they speedily bring the entire 
mass to an equilibrium of minimum yield and uniformity of admix- 
tures. As the country elevator furnishes the chief supply of seed for 
the general cropping areas, an area of wheat does not represent one 
variety but several, and many types of infectious diseases which ac- 
cumulate in seed and soil. In other words, we have no reliable basis 
of holding a crop to standardization and the work of each cereal crop 
improver and public educator on breeding dies with him. ' As to the 
truth of this one could cite many instances, as Wellman, Haynes, and 
Saunders. 



BOLLEV: FIELD CROP INSPECTION. 



201 



These are strong assertions, but are easily maintained to the satis- 
faction of any person who knows field and market conditions. In 
the corn States corn culture is so overdone in large districts that the 
soil and seed is contaminated with fusarial types of fungi and other 
corn-root and seed-infecting organisms. The seed is generally re- 
duced in vitality and the soil is so infected that in spite of the cultiva- 
tion which is a necessity in that crop, good disease-free seed often 
fails to germinate properly in good fertile soil. This is but the story 
of the cotton crop, the flax crop, and the wheat crop over again. 

THE WAY OUT. 

^^lthout attempting to argue the matter further, I propose in every 
cereal producing State a law authorizing field crop inspection, seed 
certification, seed standardization, and seed sales lists, all to be under 
supervision of an officer who holds his position, not thru local or 
political appointment, but because of his position as an investigator 
and educator associated with and directed thru the proper educa- 
tional board. The law should be of such scope as to afford the basis 
for proper educational propaganda which would come as a necessary 
adjunct. It should carry funds sufficient for demonstrations and 
field work in the laying out of seed plots for standardization work. 
It should carry sufficient funds to allow a proper survey of every 
township, so that there may be a local supply of seeds which may be 
looked upon by the residents of that township as standard stuff of 
a given variety, and so inspected that it is reasonably free from the 
infectious diseases characteristic of the crop. The law should be 
equitably drawn and should be so worded as to allow of enforcement 
in the face of willful violation. 

It is, I think, self-evident that the work of crop inspection, stand- 
ardization, certification, and seed listing should be free for all 
citizens, consumers as well as growers. Further, those who do the 
certifying and listing should not be dependent for their positions on 
the number of bushels standardized, certified, and listed. This is 
perhaps the chief argument against the fee system. No citizen 
should be able to charge or think that the fee pays for the work. 

It may be asked why the necessity? Simply because (i) the 
States and Nation are creating many varieties, perhaps valuable ones 
at great expense, only to be lost inside a few seasons of general 
cropping and marketing thru admixtures, disease contamination, and 
deterioration. If not lost, their qualities are quite camouflaged by 
the products obtained. (2) Seed inspection laws which only inspect 



202 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

in the bag or bin in the place of seed sales after the seed is sold off 
the farm have failed and are failing to insure seed and crop 
improvement. 

I do not mean by this that such inspection laws have not pre- 
vented the sale of much worthless seed. Under the present seed 
laws it has been possible to prevent the sale of large quantities of 
perfectly nonviable seeds and it has been possible to prevent the sale 
of seeds containing cjuantities of noxious weed seeds. It is not in 
this sense that I claim they have not succeeded, but rather that in- 
spection after the crop is sold cannot improve the crop. Indeed, it 
may even deteriorate until there is really nothing worthy of the in- 
spections and analysis wasted upon it. The seed merchant can only 
sell that which he buys and that which he buys cannot be better than 
what the farmers grow\ If we are to improve that which is grown, 
it is evident that the inspection must be commenced earlier and with 
the cropping processes. One cannot improve that which is in the 
bin by inspecting it, he can only refuse to allow it to be sold until 
graded or cleaned. As, however, the admixtures are usually such 
that cleaning machinery cannot remove them, no amount of inspection 
will improve the breed and sanitary qualities of seed at this point. If 
the inspection starts on the farm and goes into operation with a view 
of aiding the grower to produce a better crop to be sold for seed for 
sowing purposes, or even for commercial purposes, then the money 
involved in the inspecting and in educating the public acts directly, 
and readily leads to an improved purebred seed plot. Within two or 
three crop generations it results in an entire farm crop of improved 
or pedigreed seed in sufficient quantity to fill wholesale seed houses 
or manufacturing warerooms. A sufficient number of such prop- 
erly inspected crops will provide for the township and county needs 
and the process soon becomes infectious on adjacent farms. Thus 
standardization of varieties and proper recording of the growers may 
be established and thru authorized lists the grower of improved or 
pedigreed seed may be brought into authentic touch with those who 
wish to use the seed on the land. Seed inspection thus becomes at 
once a constructive process for improvement of seed quality and a 
means whereby records may be estabhshed and kept so that the breed 
may not be lost thru misrepresentation or ignorance. 

Some may say that this can be done thru cooperative breeders' 
associations and by constantly renewed educational campaigns. That 
this is not possible, never has been done, and cannot be done because 
there is no tie to prevent such organizations running wild or dying 



BOLLEY : FIELD CROP INSPECTION. 



203 



when the originators die, is self-evident and a historic fact. Such 
organizations usually die a natural death through the action of greedy 
memb'ers and false advertising propaganda. Who is there to check 
up the cooperative breeders' associations? Seed improvement must 
last thru the life of many men and for this there must be plans 
based on established law. 

The one thing that can be said about our present haphazard method 
of breeding, seed recommendations, and educational propaganda is 
that all die out. Thru this system or utter lack of system there has 
accumulated an enormous number of synonyms, and numerous varie- 
ties mixed and jumbled into junk lots and misbranded kinds and the 
Nation quarrels as to how such cereals may possibly be graded for 
commercial purposes. These methods, with the craze for introduc- 
tion of new kinds and the accompanying fallacies that varieties run 
out have so beset our agricultural public and plant-breeding workers 
that many able men are spending their time on the study of syn- 
onyms and the separation of varieties which, were the tasks accom- 
plished, would be lost w^ithin three years should they cease their 
labors. 

Even in potato culture, there are getting to be so many varieties 
and so much disease contamination in the chief potato districts that 
one can scarce load a car of a single variety reasonably fit for use as 
seed or even commercial marketing without hand selection and dis- 
infection. What then must be the status with reference to wheat, 
oats, and barley ? 

The average person seldom sees anything smaller than potatoes 
and walnuts accurately, and this is literally true in regard to cereals. 
Some claim there is no necessity for such work because the national 
grain grades will eventually take care of this matter or should take 
care of it. Xothing can be farther from the fact. Nothing can be 
farther from possibility, for the national grades do not recognize 
variety. All hard spring wheat looks alike to the elevator and com- 
mercial man regardless of the variety. In milling and for feed pur- 
poses, in actual fact, it should make httle difference. These should 
not concern themselves with variety further than the matter of kind. 
For commerce and manufacturing national grades are an essential 
necessity in order that all may be properly safeguarded. They 
should recognize qualities, as hard and soft, damp and dry, bright 
and moldy, etc., but they have little concern with variety. If they 
should, under present conditions, sufficient elevator bins could not be 
constructed to separate the varieties in any large cropping district. 



204 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

In fact they do not. The fact that a sample of wheat is of No. i 
cereal quality, as No. i hard spring, does not at all insure its seed 
value. It may bear all the weed infection, disease infection, and 
types of wheat admixtures to which that particular region is heir, and 
the more the national grading system attempts to separate varieties 
in the grading system, the more certainly will their processes be 
damaging to agriculture. 

The seed proposition must stand on its own merits and must be 
recognized as separate from the manufacturing proposition. If we 
care for crop improvement we cannot allow the seed standards in 
cereal cropping to be based upon national standards for flour and 
feed manufacturing. Nor can we as agronomists allow those in 
charge of the national grades to claim without rough challenge that 
they are protecting the varieties. As long as our farmers believe or 
are taught to believe that they have some protection from this source 
it will be possible for our wholesale seed houses to buy " No. i 
Northern Spring " or whatever the designation may be and sell it 
back to our farmers for seed as a basis for crop production. 

FIELD SEED CROP INSPECTION. 

The process of proper field crop inspection for seed production and 
seed standardization is a very simple one when properly authorized 
and put into operation. It can be done under any conscientious 
educational official administration of the State and can be con- 
tinuous from one generation of officers to another without loss of the 
underlying methods and records. The natural home of such crop 
inspection would be associated with the work of the agricultural col- 
lege and experiment station, where experts should exist or where it 
should be possible to develop experts in seed and crop standardiza- 
tion. The work can very naturally and properly be centered around 
the work of the pure seed office of the State. In its essentials it con- 
sists in the sending of competent inspectors to inspect the growing 
crops of those who claim to be growing seeds for sale for sowing 
purposes, or for special commercial enterprises. This inspection of 
the crop or stock may be done at any time before it is sold off the 
farm on which it is grown, but the proper time for such inspection is 
when the grain is in head, when even a novice in agronomic or 
botanical work need make no mistake as to variety, the percentage of 
admixture, and the possibility of disease infection, as scab, rust, ergot, 
smut, etc. A certificate should follow final inspection of the seed 
in the pure seed laboratory following harvest and thrashing. A State 



BOLLEY : FIELD CROP INSPECTION. 



list should be published showing the name of the grower, his address, 
and the variety and quantity of seed saved for sale as seed, and its 
authorization should be based upon the certificates as issued. Such 
State laws should specify various grades of improved grain, as "bulk 
seed of sufficient purity for use in special commercial processes or in 
general cropping," " improved seed," " pedigreed seed," etc. 

Suffice it to say that this State listing necessitates official records 
of pedigrees and makes possible standardization and retention of 
varietal standards of quality. The whole process tends to form a 
proper educational basis for seed and crop improvement. Finally, 
the lists put any man who Welshes to use the particular seed in touch 
with the man who is able to provide it. Thus good seed gets used 
on the land. The grower and the public are assured ag'ainst having 
the work of proper tillage and proper crop rotation destroyed or set 
aside thru the use of false, unknown, or deteriorated varieties. The 
whole process tends to insure final crop standardization and is the 
necessary foundation for final establishment of marketing standards. 

In North Dakota the process here outlined is not a matter of 
theory, but has been in operation on a part of the crops since 1909, 
and quite extensively in operation since 1911. Some hundreds of 
thousands of bushels of seed have been sold under the State list. We 
have made a beginning step on the right road looking toward cereal 
crop improvement. \Mien a farmer or wholesale seed merchant once 
becomes imbued with the idea of standardized seed of a known 
quality, sold under certification, and if necessary under lead seal, he at 
once sees the necessity of following other processes of crop improve- 
ment, which follow as natural corollaries. Thus, one will not be apt 
to put such seed into lands which are weed infected, disease infected, 
or contaminated with other sorts of grains of the same kind, or junk 
the bulk product with inferior stuff on the commercial market. Im- 
provements in lines of tillage and crop rotation must and will follow 
upon seed standardization as naturally as day follows sunrise. At 
present there is no real necessity of much improvement in tillage and 
crop rotation methods, for the seed used, very often, is of such 
quality from a sanitary and breeding standpoint as to thoroly offset 
any improvement that might be expected from better tillage methods 
and improved methods in soil sanitation. 



206 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



AMERICAN HUSBANDRY, A MUCH OVERLOOKED 
PUBLICATION/ 

Lyman Carrier. 

This review is written to call attention to a 2-Violiime publication 
on American agriculture issued in London in 1775. The author does 
not give his name, but uses the pseudonym, " An American." L"n- 
fortunately, this publication, American Husbandry, has been generally 
overlooked by bibliographers of English and American literature. 
Allibone (i)- does not mention it, neither does Loudon (6) or Ale- 
Donald (7), nor does it appear in the review of Colonial writings in 
the American Cyclopedia of Agriculture. Sabin (9) has an entry, 
" American Husbandry, see Arthur Young," that may refer to these 
books or that may have meant a chapter by that title in Young's 
" Annals of Agriculture," as Sabin's bibliography was never com- 
pleted. Cushing (3) lists 38 different writers who used the pseu- 
donym, An x^merican," but does not mention American Husbandry 
and none of the authors given is at all likely to have written this 
work. The Farmers' Magazine in 1801 refers to Bordley's (2) book 
as *'the first American work upon practical husbandry which has 
come into our hands." 

An extensive criticism of American Husbandry appeared in the 
London Monthly Review of January, 1776. Obadiah Rich (8) lists 
it. Flint (4) speaks of it as An exceedingly interesting work," and 
Trimble (10) refers to it as an indispensable source" of informa- 
tion on Colonial agriculture. 

SCOPE OF THE WORK. 

The author describes the soil, climate, and agricultural practices 
and products of the English colonies in America, beginning with 
Nova Scotia and Canada and following in geographical order with 
New England, New York, New Jersey, Pennsylvania, Maryland, 
Virginia, the Carolinas, Florida, and the West Indies. The agri- 
cultural possibilities of the Ohio and ^Mississippi valleys were empha- 

1 Contribution from the Bureau of Plant Industry, United States Depart- 
ment of Agricuhure, Washington, D. C. Received for publication March 18, 
1919. 

2 References are to "Literature cited," page 211. 



carrier: AMERICAN HUSBANDRY. 



207 



sized. In addition to this descriptive matter the objectionable farm 
practices are mentioned and remedies suggested. The staple com- 
modities which each colony produced or was capable of producing are 
discussed from the standpoint of their value to Great Britain. State- 
ments showing the capital necessary to establish a farm and the prob- 
able receipts and expenditures connected with its operation are given 
for most of the colonies. Direct comparisons are frequently made 
between the agricultural possibilities of America and England, with 
the advantages and disadvantages pertaining to each country. 

PURPOSE OF THE WORK. 

These books appear to have been written largely for the benefit 
of England and it was probably intended that they would be read 
in England more than in America. The author states I particu- 
larly mean to explain everything in my power concerning the country 
management of America from its being so little known in England." 
This publication would have been very valuable to English emigrants 
to America, but a deeper political purpose appears back of their 
composition — to clear up the dense ignorance in regard to the colonies 
which prevailed in the English Government at that time. Had they 
been published earlier and given wide circulation they might have 
changed the histories of two great nations. At the time they ap- 
peared the Boston Tea Party and the battle of Lexington and Con- 
cord had put a stop to sober reasoning on both sides of the Atlantic. 

LITERARY STYLE. 

One of the most striking features of these books is the directness 
with which the author goes at his subject. There is a happy absence 
of the chapter of apologetic excuses for undertaking the great task of 
writing a book so customary in eighteenth century publications. 
Neither is there the misplaced theological discussion so common in 
the waitings of the early preacher-agriculturists. They are as easy 
to read as any modern book on the subject, and are far superior to 
any .other colonial agricultural writings. Another feature is the 
thoroness with which the different matters are discussed. 

A fault which is quite noticeable is the unnecessary repetition of the 
same observations under different phases of the subject. 

CHARACTER OF THE PUBLICATION. 

The value of these books at the present time is due to the agricul- 
tural and not the political information which they contain. Com- 



208 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



pared with the agricultural hooks published in the last half of the 
eighteenth century either in America or Great Britain, they stand 
far in advance of their time. They are also of much value from a 
historical point of view. The agriculture of the colonists, as de- 
scribed in American Husbandry," differs considerably from that 
described in the agricultural histories and retrospects written in the 
past half century. In many of the latter, conditions have been 
colored to show a wonderful advancement in farming since the United 
States became a nation. As a matter of fact there has not been any 
great improvement except in the invention and wider use of farm 
machinery. The ordinary farm practices of his period did not meet 
the approval of the author of American Husbandry any more than 
present practices meet the standards of modern writers. The dis- 
tinctly American practice of cropping a piece of land until it would 
not give a profitable yield and then turning it out for nature to restore 
the fertility while the same process was repeated on another area was 
strongly condemned. The closing chapters of the second volume, 
which deal with the possibilities of the colonies becoming independent 
and with the British colonial policy, must be classed among the most 
remarkable writings of pre-revolutionary times. They should be 
read by every student of colonial history. 

Perhaps the nature of these books may best be shown by a few 
direct quotations. 

I need not observe here that in all countries one great principle of husbandry 
is the procuring and using as much dung and manure as possible : the farmers 
of New Jersey cannot raise hemp for exportation in large quantities for want 
of more manure; yet do they give into one practice which is very negligent; 
they leave the straw of most of the buckwheat they cultivate about their fields 
in heaps ; they find their cattle will not eat it and so think there is no other use 
for it, but surely these men might reflect on the importance of litter, as well as 
food for cattle, in the consumption of their hay and other straw they might 
certainly use far more than they have or perhaps can have; but to possess it 
on their own farms without using it is unpardonable; nor is it a universal prac- 
tice which keeps the whole country in countenance, for there are some planters 
who have better ideas, use all their straw carefully for litter and the advantage 
which these men reap from the practice ought surely to make the rest follow 
their example. There is no error in husbandry of worse consequence than not 
being sufficiently solicitous about manure ; it is this error that makes the 
planters in New Jersey and our other colonies seem to have but one object 
which is the ploughing up fresh land. (Vol. I, p. 143.) 

In discussing the agriculture of the New York colony he states : 

They should never exhaust their lands; and when they were only out of 
order they should give them what ought to be esteemed the most beneficial 



carrier: AMERICAN HUSBANDRY. 



209 



fallow; that is, crops which while growing received great culture at the same 
time that they do not much exhaust the soil; such as all sorts of roots and 
pulse and every kind of leguminous plant with the various kinds of clovers. 

A cropping system he recommended for one of the North Central 
Colonies was: i, Indian corn; 2, potatoes; 3, Indian corn;. 4, peas or 
beans; 5, barley; 6, clover; 7, wheat. 

In this system no two exhausting crops come together, peas or beans and in 
general the plants which bear a leguminous flower being of a different nature 
from corn in this respect. (Vol. I, p. 457-) 

An experiment station was another of the things he advocated for 
the improvement of agriculture. He says : 

It is impossible to know what the merit of the plants indigenous in these 
colonies is unless there is a plantation established at the public expense under 
the direction of a skilful botanist and one perfectly well acquainted with the 
practical as well as the theory of agriculture. In such a plantation improve- 
ment might be made in the culture of tobacco; vineyards might be planted and 
cultivated, both of the native vines and also of foreign ones. Experiments 
might be made on the culture of silk. All the native plants like those I have 
just mentioned which promised anything of utility might be brought into cul- 
ture and trials made of their worth as materials for manufacture. Such a 
plantation well supported would be attended with some if not all those excel- 
lent consequences which flowed from the gardens of the Dutch East India 
Company at the Cape of Good Hope. (Vol. I, p. 275,) 

Cotton we import from Turkey at the expense of above two hundred thou- 
sand pounds a year; this commodity agrees well with the soil and climate of 
Georgia, especially those of the back parts of the province; I am sensible that 
our West India islands would produce it but the land which is so occupied 
there would produce more valuable staples ; there we want land, but on the 
continent is more land than we know what to do with. (Vol. II, p. 40.) 

The cotton they cultivate here (eastern Louisiana) is a species of the white 
Siam. This East India and annual cotton has been found to be much whiter 
than what is cultivated in our colonies which is of the Turkey kind; both of 
them keep their color better in washing and are whiter than the perennial 
cotton that comes from the islands though this last is of a longer staple. (Vol. 
11, p. 84.) 

THE AUTHOR. 

It would appear from a study of American Husbandry that the 
author had lived both in England and America, and that he was 
loyal to Great Britain. He evidently had a scientific training, in- 
cluding a knowledge of botany, and was most familiar with the 
agriculture of ^'irginia and ^Maryland, but had also visited Penn- 
sylvania and probably New England. A reasonable assumption 
would be that he had some connection with the British government 
as evidenced by the continual economic discussion of a political 



2IO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

nature, and one might reasonably suppose that these two books were 
not his first and only literary production. 

The only man who seems to answer all of these requirements is 
Dr. John Mitchell, best known as a botanist and memorialized by 
Mitchelli re pens, the pretty little partridge berry. As another paper 
bearing on the life of Doctor Mitchell has been prepared for publica- 
tion elsewhere, only a brief account will be given here. Doctor 
Mitchell was born and educated in Great Britain and graduated an 
M.D. He came to America early in the eighteenth century and 
settled at Urbanna on the Rappahannock River in eastern Virginia. 
His first literary work seems to have been a small treatise on botany 
and zoology in 1738, followed by another in 1741 in which he pro- 
posed 30 genera of plants. These were published in 1748 by Doctor 
Trew of Nuremburg. Doctor Mitchell sailed for England in 1746 
with an extensive botanical collection, but a Spanish privateer cap- 
turned- the ship and took his possessions. Mitchell reached England, 
but was compelled to give up his botanical work. He was made a 
fellow in the Royal Society in 1748 and two of his papers may be 
found in the Philosophical Transactions of that Society. About 1753 
he was employed by the British Ministry to prepare a map of North 
America which was pu'blished in 1755. This map has been recog- 
nized as the most authentic of the colonial period and was the one 
used at the peace council at the close of the Revolutionary war. Ac- 
companying this map Mitchell submitted a report which was pub- 
lished in 1757 entitled The Contest in America between Great 
Britain and France, by An Impartial Hand." Another anonymous 
book which has generally been credited to Dr. Mitchell was entitled 
"The Present State of Great Britain in America," 1767. 

In addition to the publications mentioned above this study has re- 
vealed two other anonymous publications which were undoubtedly the 
work of Doctor Mitchell. The first of these was "An Account of 
the English Discoveries and Settlements in America" in the revised 
edition of Harris' Voyages and Travels published in 1748 and which 
may be found also in Pinkerton's Voyages and Travels (1819). The 
second was entitled " A New and Complete History of America." 
This was issued in 1756 and consists of three volumes. The third 
volume ends abruptly in the middle of a word and the set was never 
completed. This is a very rare and little known publication. 

As Doctor Mitchell died in 1768 or seven years previous to the 
publication of American Husbandry, the manuscript must have been 
edited by another. There is evidence of an attempt to disguise 



carrier: AMERICAN HUSBANDRY. 



211 



Doctor ^litchell's part in its preparation. A careful comparison of 
these books with the other pubHcations generally credited to Doctor 
^litchell, together with those anonymous books mentioned above, 
leaves no reason for doubting that Doctor Mitchell was the author of 
American Husbandry and that the manuscript was in a fairly com- 
plete condition at the time of his death. 

American Husbandry may be found in The Boston Athenaeum 
Library and the Boston Public Library, Boston Mass. ; the Phila- 
delphia Public Library and the Pennsylvania Historical Library, 
Philadelphia, Pa. ; the Library of the Department of Agriculture 
and Librar}- of Congress, Washington, D. C. ; The Virginia State 
Library, Richmond, Va. ; The Library of the Wisconsin Historical 
Society, Madison, Wis., and the Printed Book Department of the 
British Aluseum at Bloomsbury, England. It is probably to be 
found in some libraries other than the ones mentioned above. 

LITERATURE CITED. 

1. Alliboxe, S. Austin. British and American Authors. 1870. 

2. BoRDLEY, J. B. Essays and Notes on Husbandry and Rural Affairs. 1799. 

3. CusHiXG, Wm. Initials and Pseudonyms. 1885-8. 

4. Flint, Chas. Rpt. U. S. Comr. Agr. 1866, p. 25. 

5. Farmers' Magazine, 5th ed., vol. II, p. 311. Edinburg, 1801. 

6. Loudon, . Agricultural Bibliography of North America in Encyclo- 

pedia of Agriculture, 4th ed. 1839. 

7. McDonald, Donald. Agricultural Writers from Sir Walter of Henly to 

Arthur Young. 1908. 

8. Rich, Obadiah. BibHotheca Americana. 1846. 

9. Sabin, Joseph. Dictionary of Books Relating to America. 1868. 

10. Trimble, Wm. Introductory Manual for the Study and Reading of 
Agrarian History, p. 31. 1917. Published by the N. Dak. Agr. Col., 
Agricultural College, N. Dak. 



212 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



THE EXPERIMENTAL ERROR IN FIELD TRIALS/ 

H. H. Love. 

Under the title, Studies concerning the eHmination of experi- 
mental error in comparative crop tests," Professor Kiesselbach^ 
points out the occurrence of experimental error in many kinds of 
crop tests. The bulletin is well prepared, contains much of value, 
and should be carefully studied by anyone engaged in comparative 
trials of any sort. 

It is not the purpose here to review the bulletin in detail, but rather 
to point out certain cases which it seems might well be considered 
further. The first is competition that apparently occurs between 
different rows and the second the conclusion reached regarding the 
use of the probable error. 

First, in regard to the competition between rows. The author 
compares the competition between thin and thick stand and obtains 
in this case a much smaller yield from the thin planting. The rate 
of planting is not given, unfortunately, so we cannot discuss this 
from that standpoint. Another point is not stated, that is, whether 
the series were so arranged that the rows ran from east to west or 
north to south. These points are omitted, altho the author (page 
89) urges that the methods used by experimenters should be given. 
We have reason to believe that some of these rows at least extended 
east and west, so that competition would no doubt occur and perhaps 
be very marked in certain cases. As the direction of the rows is not 
made clear, it is well at this time to emphasize this point. 

In certain experiments conducted at Ithaca, N. Y., where the rows 
run from north to south and data are available it is shown that there 
is little competition between varieties ; in fact, there is so little be- 
tween the ordinary varieties usually tested in any one locality that no 
correction would be necessary. Perhaps for other conditions the 
results would be different. In order to obviate any criticism of this 
method it might be well to follow the plan of arranging varieties 

1 Contribution from the Department of Plant Breeding, New York State 
College of Agriculture, Ithaca, N. Y. Received for publication February 26, 
1919. 

- Kiesselbach, T. A. Studies concerning the elimination of experimental 
error in comparative crop tests. Nebr. Agr. Expt. Sta. Research Bui. 13. 
1918. 



love: experimental error in field trials. 



213 



so that late sorts are grown together and the earHer ones together. 
In other words, the different sorts could be so arranged that they 
grade into one another as regards yield, earliness, and the Hke. 

Xow in regard to the use of the probable error the following is said 
for fear some persons might be misled and agree with the author 
in his conclusion. It is to be hoped that even greater use will be 
made of the probable error in interpreting results. A thoro study of 
its application will show its possibilities. 

Professor Kiesselbach assumes that a field which has been sown 
to one variety of oats is uniform and makes 50 groups of 4 adjacent 
plats. He then states that 

If it is permissible to assume that one group of 4 duplicate plats is com- 
parable with another group of 4 plats in the same field, then it would also seem 
permissible to assume that in the present instance, the mean yield for the 
entire 200 similarly treated oat plats should represent the correct yield or true 
value of any or all of the individual groups within the field. If this assump- 
tion be made with the adjacent duplicate plats (Table 32), the actual error of 
these group means exceeded their probable error approximately o, i, 2, 3, 4, 5, 
6, 7, 8, 10, II, and 15 times respectively in 9, 5, 7, 7, 8, 4, 4, i, 2, i, i, and i 
groups. 

In the first place his assumption is wrong for the field is not homo- 
geneous as the following correlation will show. It is clear that the' 
field is spotted and that the average yield of the 4 adjacent plats 
shows a gradual decrease from one side of the field to the other. 
The heterogeneous nature of the field is well shown if Harris' method 
of determining the heterogeneity is used, for r= .206 ± .046. When 
such heterogeneity exists it is surprising that the deviation divided by 
the probable error as given in Column 11, Table 32, is not greater 
than it is and that 30 out of the 50 cases actually show that the 
deviation is not more than 3.8 times the probable error (meaning 
odds of about 30: i). 

The author states that 

Among the 50 groups of adjacent plats, one group yielded 14.2 bushels less 
and another group 7.3 bushels more per acre than the 200-plat mean. These 
extremes represent an experimental error of 21.5 bushels since both should 
have yielded alike if the method of comparison were reliable. 

What are we to conclude from this? If we compare the two 
groups, Xos. 30 and 50, with each other and consider their probable 
errors we see there is a difference of 21.5^12.55 bushels. Does 
such a dift'erence mean that the use of the probable error should be 
discontinued? Not at all — it means that the method of grouping 4 



214 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

adjacent plats is at fault. It means that the average of 4 plats in 
one part of this field does not always represent the average of the 
entire field. Is there anything that points this out any more clearly 
than the probable error? Shall we refuse to use the probable error 
because it points out inaccuracies in our methods ? 

Now let us consider these data further. Instead of using the 
method for determining the probable error that the author used, 
which was to determine it from the standard deviation, some may 
prefer to use the more common method of determining the probable 
error by Bessel's or Peter's formula. The probable errors determined 
in this way will be slightly higher in value than the others and 
perhaps for a few individuals be just as rehable. When the prob- 
able errors are recalculated and the average yield of each four plats 
compared with the average yield of all the plats (with its probable 
error) the difference and the probable error of the difference can be 
obtained. It is this probable error that would then be used^ to de- 
termine values for Column 11. When this is done we find the 
following: 

Number of groups 01 2 3456789 10 11 15 

Group means exceed probable error: 

When the author's method is used 957 7844120 i i i 

When above suggested method is used 99612343111 o i 

This shows more of the groups falling in the lower classes so far 
as the ratio of deviation to the probable error is concerned. 

Now when the grouping of these plats is made by combining 
systematically distributed plats the results are very different. There 
are only 3 groups v^hose ratio of deviation to probable error is greater 
than 3.8. If these were recalculated on the basis suggested above 
and the comparison made between the deviation and the probable 
error of the difference none of the plats would show a ratio greater 
than 3.8. 

Now if we take the two groups showing the greatest plus and 
minus deviations in average yield we find that one yields 84.3 ± 1.45 
and the other yields 72.0 ±: 3.02. The difference between these two 
is 12.3 =t 3.35 which gives a ratio of 3.67:1. If the probable error 
is calculated on the other basis mentioned above, the probable error 
of the difference is 3.88 and the ratio only 3.17 : i. Thus, we see that 
the systematic distribution of the plats gives results such that the 
average of any four plats considered in the light of the probable error 

^ The probable error of the difference should have been used to determine 
Column II in Tables 32 and 33. 



love: experimental error ix field trials. 



215 



will better represent the yield of the field. Xow have we not here 
an excellent illustration of the value of the probable error for in the 
first method of grouping it shows that the method of grouping is not 
correct and in the second it shows that the method of grouping is 
such that any group fairly well represents the yield of the field as a 
whole ? 

The author points out that while the probable error is low, espe- 
cially in the first method, the actual difference between groups is con- 
siderable. This is true in a number of cases and would be expected 
since the grouping is such that four low or four high yielding plats 
may be taken together. Their probable error might be low and yet 
the yield dift"er somewhat from the average yield of the entire field. 
We do not expect the probable error to be as large as the actual 
dift'erences obtained in such grouping as that of grouping 4 adjacent 
plats in a field of such marked heterogeneity. 

The author cites a case of the limitation of the probable error as 
follows : 

Small Grain Row Tests. — In Tables i to 7 were given the relative small 
grain yields of rate-of-planting or variety tests in alternating nursery rows. 
The plats were replicated 50 times and the probable error of the mean yields 
is indicated. The yields in these plats were subject to two sources of error, 
namely, soil variation and plat competition. Corresponding tests were also 
made in five-row plats relatively free from plat competition and subject pri- 
marily only to soil variations. 

In Table i (1913) the yields of the thick and thin planted wheat rows were, 
respectively, 389 + 5.3 and 264 + 3.8 grams. Altho the probable error for 
each yield is less than 2 percent the actual error of the relative yields due to 
competition is 24.4 percent. In 1914 the yields of the thick and thin planted 
wheat rows were respectively 327 + 6.66 and 115 + 3-6 grams. Altho the prob- 
able error for each yield is only 2 percent, the actual error of the relative 
yields, due to competition, is 56.8 percent. 

Now this does not show the limitation of the probable error at all. 
The probable error of the 50 row plats and the 50 five-row plats is 
low in each case. This shows that the results obtained in each case 
are very reliable. In each case a different experiment has been per- 
formed. Competition causes a small yield for the thinly planted 
rows, which is apparently not so marked in the plats. It does not 
seem possible that any one would think that the probable errors of 
the two separate tests would be large enough to encompass the abso- 
lute differences due to the different methods. If such were the case 
the results with so large a probable error would be of no value what- 
soever. Such an assumption regarding the probable error is wholly 



2l6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

unwarranted and erroneous. What the probabie error shows is that 
(as stated above) the resuhs are rehable and that in one case (rows) 
competition has a greater effect than in the other (plots). Such 
examples do not at all show the limitation of the probable error. 
The author further states that 

Crop tests are subject to such a multitude of local environmental influences 
that errors in them cannot be regarded as occurring according to the formulas 
or rules of chance calculated from purely mechanical observations. The prob- 
able error calculation may apply, for example, to the chance drawing of black 
and white marbles from a bag at a given ratio to each other. But variations in 
crop yields are no such simple matter, and the probable error not only may 
have little significance, but may be misleading. 

Now, if the deviations from the mean of all the plats are plotted 
or if the yields themselves are plotted, we obtain a very good fre- 
quency curve belonging to one of the well known types of frequency 
curves. In order to compare the difference between such occurrences 
as plot yields and other occurrences due to chance 8 pennies were 
tossed 200 times and the number of heads recorded. Here chance 
would surely operate fairly. The 200 tosses when grouped into a 
frequency curve of 9 classes gave no better distribution than when the 
200 plot yields were grouped into a curve of 10 classes. 

Does not the author assume the law of chance to operate when 
he combines results to obtain an average for any test? If the prob- 
able error is misleading when applied to such an average (because 
it is based on the law of chance) then is not the average misleading 
because it too assumes that the results fall some above, some below, 
the true value which for no better result is expressed in the average? 



AGRONOMIC AFFAIRS. 



217 



AGRONOAIIC AFFAIRS. 

MEMBERSHIP CHANGES. 

The membership reported in the April Journal was 525. Since 
copy for that number was sent to the printer, 11 new members have 
been added and 2 members have been reinstated, while news of the 
death of i member has been received. The names of the new and 
reinstated members, with such changes of address as have come to the 
notice of the editor or the secretary, are as follows : 

New Members. 

Boyd, John B., State Normal School, Springfield, Mo. 
CoRMANY, Chas. E., State College, N. Mex. 
Davidson, A. E., Warrensburg, Mo. 

Griffee, Fred, Kans. State Agr. College, Manhattan, Kans. • 
HowAT, John, Macon, Mo. 

McClymonds, A. E., Kans. State Agr. College, Manhattan, Kans. 

Mitchell, Jacob N., 403 Exchange Bldg., Memphis, Tenn. 

Quisenberry, Karl S., Kans. State Agr. College, Manhattan, Kans. 

Raut, Alfred, Perryville, Mo. 

Smith, J. O. M., R. F. D. 14, Commerce, Ga. 

Weeks, Chas. R., Hays Branch Station, Hays, Kans. 

Members Reinstated. 

Macfarlane, Wallace, Agr. Expt. Sta., Honolulu, Hawaii. 
ToRGERSON, E. F., Dept. of Soils, Oregon Agr. Coll., Corvallis, Ore. 

Member Deceased. 
A. J. Galbraith. 

Changes of Address. 

Dillman, a. C, Northern Great Plains Field Sta., Mandan, N. Dak. 
Hagy, F. S., Belmond, Iowa. 

Laude, H. H., Dept. Agronomy, College Station, Texas. 

Martin, John H., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Sears, O. H., 123 Sheetz St., La Fayette, Ind. 

Trout, C. E., Jerseyville, 111. 

Walster, H. L., Dept. Agronomy, Agricultural College, N. Dak. 

NOTES AND NEWS. 

Brown Ayres, president of the University of Tennessee since 1904, 
died at Knoxville, January 28, 1919. Doctor Ayres was born in 
Memphis, ]\Iay 25, 1856, and was a graduate of Stevens Institute of 



2l8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Technology. Previous to his election to the presidency of the Uni- 
versity of Tennessee, he was a member of the faculty of Tulane Uni- 
versity. He was prominent in educational organizations for many 
years, particularly in the Association of American Agricultural Col- 
leges and Experiment Stations. 

Samuel M. Bain, professor of botany in the University of Ten- 
nessee since 1901 and well known for his work on diseases of red 
clover and other crop plants, died January 30, 1919, at the age of 50 
years. 

J. B. Davidson, for the past four years professor of farm mechanics 
in the University of California, is to return on July i to Iowa State 
College as head of the department of agricultural engineering, the 
position he held before going to California. 

Elmer O. Fippin, professor of soil technology in Cornell Univer- 
sity, will become director of the agricultural bureau of the Lime As- 
sociation on July I. He has been connected with Cornell University 
since 1905. 

F. S, Hagy is now instructor in vocational agriculture at Belmond, 
Iowa. 

H. V. Harlan, agronomist in charge of barley investigations in the 
Federal Department of Agriculture, sailed May 2 for Europe, to 
assist in making crop surveys in Germany and Austria for the Grain 
Corporation. 

W. D. Hurd, director of the extension service in the Massachusetts 
college since its establishment in 1909, has resigned to join the staff 
of the Soil Improvement Committee of the National Fertilizer Asso- 
ciation on June i. His headquarters will be in Chicago. 

Willis E. Johnson, formerly president of the Northern Normal and 
Industrial School at Aberdeen, S. Dak., has been elected president of 
the South Dakota State College of Agriculture, succeeding E. C. 
Perisho, who is now engaged in educational work in Europe. 

H. H. Laude, for the past several years superintendent of the Beau- 
mont (Texas) substation, is now agronomist in charge of rice investi- 
gations for the Texas station, with headquarters at College Station. 

R. D. Lewis has been appointed assistant in agronomy and J. S. 
Owens assistant in experimental agronomy in the Pennsylvania col- 
lege and station. 

John H. Martin, formerly superintendent of the Harney County 
Branch Station at Burns^ Ore., is now assistant in western wheat in- 
vestigations in the Federal Bureau of Plant Industry. He has been 
succeeded at Burns by Obil Shattuck. 

Leroy Moomaw, formerly scientific assistant in forage crop inves- 



AGRONOMIC AFFAIRS. 



219 



tigations with the Federal Department of Agriculture and recently 
returned from military service in France, is now superintendent of 
the Dickinson (N. Dak.) substation. 

Fred Rasmussen, professor of dairy husbandry in the Pennsylvania 
college, has been appointed Secretary of Agriculture for Pennsyl- 
vania and entered on his new duties January 21. 

E. B. Reynolds, formerly associate professor of agronomy in the 
Texas college, is now superintendent of substation No. 3 at Angleton, 
Texas. 

W. J. Smith has resigned as superintendent of county farms in 
Clermont and Hamilton counties, Ohio, and has been succeeded by 
H. W. Rogers, formerly foreman of the Madison County farm. 

L. J. Stadler, assistant in farm crops in the Missouri college of 
agriculture, has resumed his work after an interval in military service. 

H. C. Taylor, for many years professor of agricultural economics 
in the University of Wisconsin, has been appointed chief of the office 
of farm management of the Federal Department of Agriculture. F. 
\V. Peck, formerly of the Minnesota station, will direct the cost ac- 
counting work in this office, which is scheduled to become a separate 
bureau at an early date. 

John C. Thysell has resigned as superintendent of the Dickinson 
substation, Dickinson, N. Dak., and is now connected with the North- 
ern Great Plains Field Station, Mandan, N. Dak. 

E. F. Torgerson, formerly of the department of soil physics of the 
University of Illinois, is now assistant professor of soils in the Oregon 
college. 

H. L. Walster, formerly of the department of soils of the Univer- 
sity of Wisconsin, has been elected agronomist of the North Dakota 
station and has entered on his new work. 

Louis Wermelskirchen, formerly assistant agronomist of the Texas 
station, is now teaching agriculture in the educational division of the 
United States Army at the Fort Sam Houston base hospital, San An- 
tonio, Texas. 

Roy O. W^estley is agronomist of the Northwest substation and as- 
sistant professor of agronomy in the school of agriculture at Crook- 
ston, Minn. 

L. M. Wlnsor, specialist in irrigation and drainage at the Utah col- 
lege and station, has resigned to take up commercial irrigation work 
in Chile. 

N. E. W^inters, formerly superintendent of the Angleton (Texas) 
substation, is now engaged in extension work in agronomy at the 
North Carolina college. 



220 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

C. M. Woodworth, of the University of Wisconsin, has been ap- 
pointed to a position in the office of cereal investigations, United 
States Department of Agriculture, where he will have charge of spe- 
cial investigations of disease resistance in flax. 

Meeting of the Ohio Section. 

The annual meeting of the Ohio section of the American Society of 
Agronomy was held in Columbus, Ohio, during the week of January 
27-31, in connection with the Farmers' Week program. The pro- 
gram of the week centered around the two topics of good seed and 
the importance of legumes in a permanent system of agriculture. The 
technical session was held on the afternoon of January 30, when an 
address was given by Director Burt L. Hartwell, of the Rhode Island 
station, on The Effect of Crops on Those Which Follow as Influ- 
enced by Soil Treatments." The oflicers elected for the ensuing year 
are Wallace E. Hanger, president; F. A. Welton, vice-president; and 
Myron A. Bachtell, secretary-treasurer. 

The Western Agronomic Conference. 

The annual conference of agronomists of the eleven western States 
will be held at the University of California June 17, 18, and 19, 1919. 
The conference will convene on Tuesday, June 17, at 9 a.m., at the 
University Farm School, Davis. Wednesday, June 18, will be de- 
voted to an automobile trip from Davis to Berkeley, passing thru 
several interesting farming sections. The session on Thursday, June 
19, will be held at the University, Berkeley. The program will con- 
sist of round-table discussions, the principal topics selected for dis- 
cussion being (i) problems of power in tillage and harvesting; (2) 
soil problems related to crop production; (3) farm crop diseases and 
treatments; (4) farm crop and seed production and utilization; and 
(5) problems of teaching and leadership. All those engaged in or 
interested in agronomic work in the Western States are urged to 
attend and to participate in the program. No formal papers will be 
presented, but all will be expected to take part in the discussion. 
Charts or other illustrative material will be welcomed, and lanterns 
can be provided for slides. All those who expect to attend are re- 
quested to inform Prof. John W. Gilmore, Division of Agronomy, 
University of California, Berkeley, Cal., and to state the topic or 
topics they will be prepared to discuss. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. September, 19 19. No. 6 

THE WORK OF THE COMMITTEE ON SEED STOCKS.^ 

R. A. Oakley. 

The conditions which gave rise to the slogan " Food will win the 
war " created a flood of interest in the seed stocks of the country 
immediately. America entered the conflict, and this prompted the 
Secretary of Agriculture to appoint a Committee on Seed Stocks 
whose duties, as he expressed them in brief, were to look after the 
supply of and demand for seeds. 

Inquiries as to where seed could be purchased, where it could be 
purchased cheaply or obtained gratis, were reaching the Department 
daily in large numbers and one of the first steps taken by the newly 
created committee was to prepare partial lists of firms and indivi- 
duals having seed for sale. This was to serve in satisfying the 
nervous as well as the legitimate inquirer. These lists, while far 
from complete and often belated in their appearance, served a very 
useful purpose. Coincident with the preparation of these lists, a 
piece of work of fundamental importance was undertaken by the 
committee. It consisted of taking an inventory of the country's 
stocks of seed. This disclosed much interesting information, espe- 
cially since the committee had at its disposal the well organized ma- 
chinery of the Bureau of Crop Estimates with its large corps of 
crop reporters, the machinery of the Extension Service, and the 
newly organized Seed Marketing Section of the Bureau of Markets, 
the inspection forces of the Bureau of Chemistry, and the crop 

1 Contribution from the Bureau of Plant Industry, United States Depart- 
ment of Agriculture, Washington, D. C. Read before the eleventh annual 
meeting of the American Society of Agronomy at Baltimore, Maryland, 
January 7, 1919. 

221 



222 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

experts of the Bureau of Plant Industry. For the first time in its 
history it is believed that the Department got a real close-up view of 
the country's seed supply and learned at first hand what can happen 
in a commercial way when the country becomes apprehensive as to 
the adequacy of the supply. 

After making a quick inventory of stocks it became evident to the 
committee that its most important immediate function was to dis- 
seminate information relative to the supply of and demand for seeds. 
It also became evident that to do this successfully some organization 
would be necessary in the States. Therefore, State committees on 
seed stocks were appointed to cooperate with the Department's com- 
mittee, especially in the matter of disseminating information. The 
Federal Committee's function in this particular feature of its work 
was to act mainly as a clearing house for seed information. In this 
it is believed real service was rendered. 

Early in its investigations, the committee discovered the need for 
a carefully planned program of crop production, for the reason 
that seed is a primary as well as an incidental crop, and its produc- 
tion has an important place in the nation's cropping system. We 
were at once confronted with the relative importance to the winning 
of the war of the cereals, the forage crops, and miscellaneous crops 
such as flax, sugar beets, etc. It was found necessary to draft a 
rough but conservative chart by which to steer a course, until a care- 
fully prepared program of production could be formulated by the 
Department's special committee on production. The immediate 
need for a rational production program of some kind may be illus- 
trated by our activities in the case of flax. We found the readily 
available supply of good seed for the spring of 1917 far from abun- 
dant to sow an acreage sufficient to produce seed for our crushing 
demands, estimated on the basis of our normal demands and our 
much reduced imports. If we needed the normal quantity of flax 
produced, it would be necessary to put on a campaign among grain 
dealers and oil mills with a view to cleaning up and saving seed for 
sowing a large acreage. Of course, the flax acreage does not come 
directly into keen competition with the spring wheat and other spring 
grain acreage, but there is an appreciable overlapping. Therefore 
we had to measure the relative need for these crops and put on our 
flax seed campaign accordingly. 

The information on seeds assembled by our committee was help- 
ful in the formation of the Department's 191 7 production program, 
and in the carrying out of this program. In all the data that we 



OAKLEY: COMMITTEE ON SEED STOCKS. 



223 



found available when our committee began its work, there were 
few upon which to base a satisfactory estimate of our actual seeding 
requirements for many of our important crops. We knew, of 
course, that our seed wheat and seed rye requirements for the acre- 
age harvested, or to be harvested, in 191 7 were approximately 72,- 
000,000 bushels and 4,500,000 bushels respectively. We knew the 
approximate quantity of seed required for our acreage of all im- 
portant cereal crops. In fact, we could estimate it closely for all 
our crops for which we had annually been makmg acreage estimates, 
but there were many crops for which we had no adequate estimate 
of acreage, and among these were many of our important forage 
crops and garden vegetables. The lack of knowledge of the quan- 
tity of seed required by our farmers and gardeners for planting our 
annual acreages of some of our important crops handicapped us in 
many ways, especially in shaping recommendations for seed pro- 
duction and in formulating policies that could be recommended with 
regard to exports and imports. We soon started some machinery 
in motion, however, and while our data even now are far from 
what is desired, I am glad to say we have made much progress. 

Certain war emergency legislation which was enacted about the 
middle of the first year enabled us through the good offices of the 
Seed Reporting Service of the Bureau of Markets to get data from 
seedsmen and growers that assisted us materially in this connection. 
The Bureau of Crop Estimates put out some inquiries regarding 
acreage and seed needs that likewise produced very helpful results. 
In the first three months of our existence we had impressed upon 
us what we had already known, but probably had not appreciated to 
the fullest extent ; that is, the fact that attention cannot be called to 
a shortage of seed with a view to conserving that particular kind 
without producing a marked tendency to increase the price and en- 
courage speculation. We found it necessary therefore to exercise 
considerable discretion with regard to this point. 

On August 10, 191 7, the Food Production and the Food Control 
acts became effective. These greatly increased our work and en- 
larged its scope. The first new function which we had to perform 
under the emergency legislation developed with the fixing of the 
price of wheat. The Food Administration, which was already in 
existence awaiting legislative enactment, organized what is called the 
Grain Corporation as one of its subsidiary branches as soon as Con- 
gress provided authority for fixing the price of wheat. In a very 
short time after the adoption of the report of the " fair price " com- 



224 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

mittee appointed by the President, the Grain Corporation formu- 
lated and promulgated regulations to maintain the fixed price level 
and control the wheat supply of the country. In these regulations 
was a provision against the storing of wheat in elevators and ware- 
houses for a period longer than thirty days. It was soon found 
that the regulation, if strictly enforced, would interfere seriously 
with the storage of seed wheat, especially in the spring wheat areas 
and in the sections where winter wheat is sown before the crop of 
the same year is available, notably in the Judith Basin and other 
parts of the Northwest. The regulations did not go into effect in 
time to interfere with holding winter wheat for the 1917 sowing. 

In a conference between members of the Grain Corporation and 
the Committee on Seed Stocks a plan was developed whereby seed 
wheat and also seed rye (rye also being under the control of the 
Grain Corporation), could be held until after the sowing season had 
passed. The plan was briefly this : A dealer wishing to hold wheat 
or rye for seed applied to his zone agent, who was the Grain Cor- 
poration's representative in his zone, for a license to store these seed 
grains. If he was in good standing with the Food Administration 
his application was approved and he was instructed to submit samples 
of the lots he desired to store to the laboratory of the Committee 
on Seed Stocks in his State or zone. These samples when submitted 
were examined and notification was sent to the dealer and also 
the zone agent as to their suitability for seed. In this way very close 
supervision was kept of the stocks of wheat and rye held for seed 
by grain dealers. To stimulate the holding of a sufficient quantity 
of seed, and in recognition of the cost of storing and handling it, 
the Grain Corporation allowed the dealers to charge not in excess 
of 15 percent above the Grain Corporation's price for the same grade 
of wheat at that point. The handling of the samples entailed con- 
siderable work which was done at four points : at Minneapolis, in a 
laboratory established especially for the Committee on Seed Stocks ; 
and at Pullman, Wash., Moscow, Idaho, and Corvallis, Ore., in co- 
operation with the State agricultural colleges. Thousands of samples 
were examined and upward of a million bushels of wheat were ap- 
proved and stored under this plan, in 1917-18. The Grain Corpora- 
tion changed its plan of maintaining price levels for the crop of 
1 91 8, and the regulation limiting the storage of wheat to thirty days 
was abolished, therefore the committee has not been called upon to 
continue the work this year. 

It was found necessary to exempt regular seedsmen from the regu- 



OAKLEY: COMMITTEE ON SEED STOCKS. 



225 



lations regarding storage and from the 15 percent price differential 
for handling seed wheat. Generally speaking, seedsmen use more 
care with regard to the quality of seed wheat which they handle and 
many of them pay appreciably more than the milling price for it. 
Some of them sell it in small lots, and therefore greatly increase 
their cost of handling. Seedsmen were allowed to sell seed wheat 
and rye without regulations, but with the understanding that they 
would not profiteer, and it is believed that very little profiteering 
was done. 

The Committee on Seed Stocks has nothing but praise for the 
work of the Grain Corporation insofar as it related to the handling 
of seed wheat. It rendered even a much greater service in another 
way than the one heretofore mentioned. Crop failures made stocks 
of good wheat scarce in parts of North Dakota and Montana, and the 
desire to increase the acreage of spring wheat in the spring of 1918, 
especially in the twilight margins of the spring wheat area, caused us 
to give no little consideration to the seed supply. To be brief, the 
Grain Corporation upon our recommendation stored wheat at points 
tributary to the areas where the crop of the preceding harvest was 
short, and also shipped seed wheat into the twilight areas where the 
tendency to sow indicated a demand for seed in excess of the supply. 
Approximately 500,000 bushels were provided for such sections by 
the Grain Corporation. A very appreciable and actual gain in the 
acreage, and subsequently in the harvest, was got by this action. 

The activity of the committee which perhaps had the most direct 
bearing on the seed supply was undertaken in connection with the 
Food Production Act. Section three of this act contained the fol- 
lowing provision : 

That whenever the Secretary of Agriculture shall find that there is or may 
be a special need in any restricted area for seeds suitable for the production of 
food or feed crops, ... he is authorized to purchase, or contract with persons 
to grow such seeds, to store them, and to furnish them to farmers for cash, at 
cost, including the expense of packing and transportation. 

For this work the sum of $2,500,000 was appropriated. 

In the summer of 191 7 severe damage resulted to crops from 
drouth, especially in parts of North Dakota, Montana, Kansas, Okla- 
homa, and Texas. By midsummer it became evident that many 
counties in these States would not produce seed enough to plant 
their normal acreages the following year. The situation became 
quite alarming and in view of the ever-sounding slogan, Food will 



2 26 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

win the war," more or less hysteria prevailed. Department and State 
officials made as careful surveys as possible of the seed situation in 
the counties where the drouth was most severe, and as a result of 
urgent recommendations by State and local agencies and public 
spirited individuals it was decided to use the authority above quoted 
to relieve the apparent emergency. In taking up this work, the 
committee had the following objects in mind: (i) to conserve seed 
that was badly needed in a locality from being used for food or feed, 
or in any way passing out of availability to the locality in which it 
was produced; (2) to insure an adequate supply of good seed for 
sections where an insufficient quantity was produced; (3) to assist 
financing agencies by making it possible for them to depend upon a 
definite supply of seed at nearly a fixed price; (4) to prevent specu- 
lation in seed and hold the price to a fair level. 

After considering the needs and recommendations of the drouth- 
stricken areas, the Committee on Seed Stocks arranged for the 
purchase and sale of seed in Texas, Oklahoma, and Kansas, and in 
North Dakota and Montana. Seed of corn, cotton, the sorghums, 
and peanuts was purchased for Texas ; sorghums for Oklahoma and 
Kansas ; and barley, oats, and flax for North Dakota and Montana. 

The severe drouth of the summer of 191 7 was not the only factor 
that proved detrimental to the seed supply. On account of the very 
late season and early frosts and freezes, incalculable damage was 
done to the corn crop, and the supply of good viable seed produced 
in the northern part of the corn belt was far from sufficient for plant- 
ing requirements. In the main, this was really the greatest emerg- 
ency in our seed supply that existed during the period of the war. 
The committee recognized the seriousness of the situation early in 
the season and did what it could to call attention to the necessity 
of conducting seed-corn saving and testing campaigns. In this con- 
nection it may be said that the work of the State institutions, espe- 
cially the extension services of the various States, was admirable 
and productive of excellent results. As time went on it appeared 
that something of a more definite nature than seed-corn saving and 
testing campaigns would be necessary if an adequate supply of good 
seed-corn was to be had. The committee was therefore urged to 
allot funds from the appropriation for the purchase and sale of seed 
conveyed in the Food Production Act, and in this connection aid 
was rendered especially in Ohio, Indiana, Michigan, Illinois, North 
Dakota, and Iowa. As a sufficient supply of local corn could not 
be had in all cases, the Committee on Seed Stocks, in cooperation 



OAKLEY: COMMITTEE ON SEED STOCKS. 



227 



with the State officials, arranged for the importation of lots from 
other localities. In this connection it may be said that one of the 
largest experiments in seed-corn acclimatization was performed. On 
the advice and with the assistance of the State authorities seed-corn 
from Pennsylvania and Delaware was shipped to Ohio and Michigan, 
and from New Jersey to Indiana. It was impossible to get seed-corn 
of varieties nearly adapted to North Dakota conditions except in the 
New England States, and several cars were shipped to North Dakota 
from Rhode Island and Connecticut. In connection with this experi- 
ment it may be said that the results proved highly satisfactory. 
Possibly the long favorable season had much to do with the outcome, 
but at any rate the reports received to date are very favorable. 

As the planting season approached, the committee was urgently 
requested to use the funds at its disposal for the purpose of provid- 
ing a reserve supply of seed-corn for late planting and replanting. 
Some of the financial agencies that were assisting in providing corn 
for first planting could not use their funds for the purpose of provid- 
ing a reserve for replanting. The committee, after carefully con- 
sidering the situation, concluded that the importance of insuring a 
large acreage of corn was sufficient to warrant the risk that might 
be taken in buying seed for a replanting reserve. The seed pur- 
chased by the Department for first planting was all sold to farmers, 
but a rather large percentage of that purchased for reserve was not 
used since the weather during the planting season was so favorable 
thruout the entire corn belt that the replanting requirements were very 
far below normal. 

In its emergency purchase and sale of seed, the Committee sold in 
all enough for planting approximately 1,200,000 acres. It did not 
sell all the seed purchased. In this connection it was handicapped 
by the wording of the law which made it necessary to sell at cost, 
and therefore allowed no margin to take care of declining prices. 
In the drouth-stricken area of the Southwest, the drouth continued 
so late in the spring of 1918 that the demand for seed was very 
greatly reduced, and this, together with the fact that the supply of 
seed especially of the sorghums was much greater than had originally 
been estimated, caused a decided break in the sorghum seed market, 
and speculators offered their stocks much below cost. 

There were several points clearly brought out in connection with 
the emergency purchase and sale of seeds. Probably the most im- 
portant of all was that price goes far toward overcoming seed short- 
ages. It is really remarkable how much seed will come on to the 



228 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

market as the result of very attractive prices. The estimates of the 
requirements made by State officials were naturally in favor of their 
own interests, a fact which is to their credit. Taking everything 
into consideration, however, it is believed that the emergency pur- 
chase and sale of seed resulted in much good, not only in providing 
good seed in many localities that had practically none, but in stabiliz- 
ing prices. 

A writer in a well-known " snappy story " agricultural paper, after 
commenting on the tenacity with which the committee held to the 
seed information which it had, stated that he did not know whether 
the emergency purchase and sale of seeds resulted in a financial loss 
to the Federal Government, but he did think that the committee de- 
served credit for doing something. 

The committee was called upon to cooperate with the War Trade 
Board, an emergency organization, especially with regard to giving 
advice that would help in shaping intelligent export and import poli- 
cies. During the war, the War Trade Board virtually controlled the 
exports and imports of this country through a system of licensing. 
Seedsmen were required to obtain licenses before they were per- 
mitted to export seeds, except in a few cases where the exports were 
to Canada and Cuba. The committee found it necessary to recom- 
mend the laying of temporary embargoes in a few cases, and to ad- 
vise the restricting of exportation, especially to northern neutral 
countries who were asking in some cases for seed far in excess of 
their normal net importations. At the present time there is a 
temporary embargo on the exportation of red clover seed, except to 
Canada, and as red clover seed is now on the conservation list, licenses 
are required before lots can be exported to that country. Exports to 
Canada are being carefully watched, and only the normal require- 
ments will be allowed exportation. It appears from data that are 
available, that the supply of red clover seed now in this country 
is insufficient for our sowing demands. We are gathering data on 
this point, however, and propose to make a definite recommenda- 
tion to the War Trade Board by January 15, 1919, which will enable 
them to decide whether to retain the embargo, or to lift it wholly, or 
in part. England is anxious to get red clover seed, as are also some 
of the northern neutral countries. There appears to be a tendency 
toward the accumulation of supplies of seed in parts of Europe to 
supply the market in Russia, Germany, and Austria when it opens 
up. Manifestly we could not well spare clover seed badly needed 
here for such a purpose, but I think this country is willing to share 
seed with England to the extent of at least part of her needs. 



OAKLEY: COMMITTEE ON SEED STOCKS. 



229 



The Committee on Seed Stocks has endeavored to follow a policy 
that would aid the legitimate seed business of the country, and has 
in many cases submitted recommendations to the various war boards 
with this point in view. Almost immediately after the declaration of 
war by this country, the American Seed Trade Association and the 
Wholesale Grass Seed Dealers' Association organized war service 
committees. These committees have held briefs for the seedsmen on 
various occasions, and have served a very useful purpose in present- 
ing matters that were important alike to the seedsmen and the 
country. The Committee on Seed Stocks has had very cordial co- 
operation with these committees and wishes to take this opportunity 
to express its thanks for the willingness with which information 
and help has been offered in the war emergency. 

In looking back over the work of the committee we realize prob- 
ably more clearly than we did before that the seed production and 
distribution machinery of the country was very well adjusted, and 
that it needed only a little help and possibly control here and there 
to keep it in good working order. At the present time the seed 
supply of the country is in excellent condition, so far as its abun- 
dance is concerned. The very high price that obtained, especially 
for garden seeds, resulted in a greatly increased acreage of these seeds 
and consequently a very large harvest. We have now large surpluses 
of most of our important vegetable seeds, and it is not known to what 
extent the demand abroad will use these surpluses. 

The personnel of the committee is as follows : W. A. Wheeler, 
Chief of the Seed Marketing Section, Bureau of Markets ; L. M. 
Estabrook, Chief of the Bureau of Crop Estimates ; C. R. Ball and 
C. W. Warburton, Office of Cereal Investigations, Bureau of Plant 
Industry ; W. A. Stuart, Office of Horticultural and Pomological In- 
vestigations, Bureau of Plant Industry ; C. H. Kyle, Office of Corn 
Investigations, Bureau of Plant Industry ; J. E. W. Tracy, Office of 
Seed Distribution, Bureau of Plant Industry ; R. A. Oakley, Chair- 
man, Office of Seed Distribution, Bureau of Plant Industry; and 
A. J. Pieters, Secretary, Office of Forage Crop Investigations, Bureau 
of Plant Industry. 

We wish to take this opportunity to thank the State institutions 
and individuals for their very hearty cooperation. It was indeed 
a pleasure to work with the State committees and with the officials 
of the colleges and experiment stations. 



230 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



THE RELATION OF CERTAIN EAR CHARACTERS TO 
YIELD IN CORN.i 



H. Howard Biggar.^ 



Considerable study has been made by experimental workers to 
ascertain whether any of the various ear characters of corn can be 
used as a guide in selecting ears for high yield. 

The data in this paper deal with the relation between certain ear 
characters and yield, in five varieties of corn grown at five different 
points. The characters here considered, in their relation to yield, 
are length of ear, weight of ear, number of rows of kernels, and the 
shelling percentage. The tests from which the data were derived 
were ear-to-row tests, conducted with a view to varietal improvement. 



Montgomery (6)^ states that his results indicate the yielding value 
of a long, smooth type of ear. He also states that a medium depth 
of kernel is preferable to deep or shallow kernels. 

Olson, Bull and Hayes (7) state that close selection for high scor- 
ing ears is of no practical value in increasing the yield of corn. They 
report the following coefficients obtained in a correlation study of 
ear characters and yield with Minnesota No. 13. 



Williams and Welton (9) state that in ten years of experiments 
which they conducted the yield secured from long ears was 1.39 
bushels per acre more than the yield secured from short ears. In 

1 Contribution from the Bureau of Plant Industry, United States Depart- 
ment of Agriculture, Washington, D. C. Received for publication April 5, 1919. 

2 Credit is due the following men of the Office of Corn Investigations who 
have made measurements of ears and conducted field work with the varieties 
discussed in this paper : Messrs. E. B. Brown, G. J. Burt, H. S. Garrison, J. M. 
Hammerly, C. P. Hartley, C. E. Trout, J. G. Willier. 

3 Reference is to " Literature cited," p. 234. 



REVIEW OF PREVIOUS INVESTIGATIONS. 



Character. 



Coefficient of correlation. 



Length 

Weight 

Circumference 

Shelling percentage 



-f .098 + .040 

-f .047 ± 044 

— .052 + .041 

+ .157 ± -043 



biggar: ear characters of corn. 



231 



nine years of experiments, tapering ears outyielded cylindrical ears 
by 1.65 bushels per acre. Six years' experiments with ears having 
an average shelling percentage of 88.16 as compared with ears averag- 
ing 76.38 percent showed a slight increase in yield for the ears with 
the lower shelling percentage. 

Love (3) found that there was some relation between length and 
weight compared with yield, but that such characters as number of 
rows, average weight of kernels, and ratio of tip to butt circumfer- 
ences do not have any very marked effect upon yield. 

Love and Wentz (4), working with Funk Yellow Dent, found 
that circumference of ear was correlated with yield, but that the 
correlation was never consistently high. Their weight correlations 
were all positive but small. The correlations of yields and shelling 
percentages were all negative, and in field tests ears with a high 
shelling percentage averaged 0.692 pound per stalk, while ears of 
low shelling percentage averaged 0.753 pound per stalk. 

Cunningham (i) arranged the ears of several varieties in groups 
of long, medium and short ears. There was no correlation between 
length of ear and yield. He found that slender ears were more 
productive than ears of large circumference, and that there was no 
relation between shelling percentage and yield. 

!McCall and Wheeler (5) found that correlations of ear characters 
and yield were not consistent, and that neither length, weight, or 
density were correlated with yield. 

Hutcheson and Wolfe (2) state that they found a relation between 
length and weight and yield, but that such characters as number of 
rows and percentage of grain showed little relation to yield. 

VARIETIES USED IN THIS STUDY. 

The five varieties studied for correlation were : Selection 77, a 
large white dent grown at Piketon, Ohio; Selection 120, a large white 
dent grown at Round Hill, Va. ; Selection 1 19, a large white dent 
grown at Occoquan, Va. ; Selection 133, a small yellow dent grown at 
Oconomowoc, Wis. ; and Selection 204, a medium sized dent grown 
at Hawarden, Iowa. Four years' results are given for Selection 77, 
and three years for each of the other varieties. The relative differ- 
ences in the ear characters of the five varieties are shown in Table i, 
in which the averages of the characters for the various years of the 
test are given : 



232 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table i, — Average weight of ears, length of ears, number of rows, and shell- 
ing percentage of five varieties of corn studied. 



Variety. 


Weight of ears. 


Length of ears. 


No. of rows. 


Shelling 
percentage. 




Grams. 


Inches. 




Percent. 


Selection 77 


324 


8.4 


14.6 


86.2 


Selection 120 


347 


8.8 


12.7 


85.6 


Selection 119 


363 


8.9 


16.8 


83.5 


Selection 133 


218 


7-1 


15-3 


81.9 




257 


8.0 


173 


83.4 



The table shows that Selection 119 and Selection 120 have the 
heaviest ears, and that these same varieties have also the longest 
ears. Selection 204 and Selection 119 have ears with the greatest 
number of rows. Selection 77 and Selection 120 have ears with the 
highest shelling percentages. 

Table 2 gives the correlation coefificients of yield compared with 
weight, length, number of rows of kernels, and shelling percentage, 
for each variety in the various years. 



Table 2. — Coefficients of correlation between yield and weight of ears, length of 
ears, number of rows, and shelling percentages. 



Variety and year. 


Weight. 


Length. 


Number 


of rows. 


Shelling percentage. 


Selection 77: 
















1914 


+ .085 ± .073 


+ -177 


± .071 


+ .046 


± .073 


- .309 


db .066 


1915 


+ .261 ± .065 


+ .067 


db .071 


- .028 


± .070 


— .028 


± .070 




+ .188 ± .061 


+ .120 


± .064 


+ .025 


± .063 


- .105 


± .063 


1917 


+ .064 ± .072 


+ -133 


± .072 


— .146 


± .071 


+ .001 


± .073 


Selection 120: 
















1915 


+ .200 ± .090 


+ .175 


± .091 


— .226 


± .089 


- .148 


d= .091 


1916 


+ .076 ± .083 


+ .001 


± .083 


+ .062 


± .082 


+ .276 


± .077 


1917 


+ .200 ± .091 


+ .279 


± .090 


- .025 


± .095 


- -117 


± .093 


Selection 119: 
















1915 


+ .296 ± .074 


+ .231 


± -079 


+ .063 


± .081 


+ .067 


± .082 


1916 


+ .131 ± .083 


+ .354 


± -075 


- .147 


± .082 


- .063 


± .084 


1917 


+ .565 ± .061 


+ -330 


± .081 


- .131 


± .088 


+ -155 


± .088 


Selection 133: 
















1912 


+ .070 ± .079 


+ .063 


± .080 


— .007 


± -079 


- .370 


± .076 


1913 


+ -334 ± -072 


+ .381 


± .071 


+ .061 


± .081 


— .017 


± .081 


1914 


+ .130 ± .070 


+ .301 


± .066 


+ .015 


± .071 


+ .166 


± .069 


Selection 204: 
















1916 


+ .145 ± -093 


+ .082 


± .096 


— .024 


db .095 


- .368 


± .082 


1917 


— .074 ± .062 


+ .068 


± .064 


— .040 


± .063 


+ .042 


± .063 


1918 


+ .097 ± .075 


+ .276 


± .071 


+ -055 


± -075 


- .263 


± .070 



RESULTS. 

All of the weight correlations are positive, with the exception of 
that for Selection 204 in 191 7. These positive correlations range 
from + .07 for Selection 133 in 1912 to + .565 for Selection 119 in 
191 7. In three cases the probable error is greater than the coefficient. 



biggar: ear characters of corn. 



233 



In the case of Selection 119 in 1917, the coefficient is nine times the 
probable error. 

In every case there is a positive correlation between length and 
yield, ranging from + -Cm^i to +.381. In four cases the probable 
error is greater than the coefficient. The relation of length to yield 
will be taken up more fully in Table 3, in which the long and the 
short ears for each variety in each year are compared as to yield. 
The ears of each variety were divided into approximate halves repre- 
senting long and short ears. The table gives the average length of 
each set of ears, the increase of longs over shorts in percentage, and 
the increase in bushels per acre, allowing 50 bushels per acre for the 
minimum yield. 



Table 3. — Data on correlation between length of ears and yield. 



Variety and year. 


Average length. 


Correlation co- 
efficients (all 
plus). 


Increase of longs over shorts. 


Long ears. 


Short ears. 


Percent. 


Bushels.a 




Inches. 


Inches. 








Selection 77: 












1914 


8.7 


7.6 


.177 


1.8 


.90 


1915 


9-5 


8.4 


.067 


1-3 


.65 


1916 


8.8 


7.8 


.120 


- -5 


•25 


1917 


9.0 


7-7 


.133 


1.2 


.60 


Selection 120: 












1915 


8.7 


7-7 


.175 


1.6 


.80 


1916 


9.4 


8.4 


.001 


— 2.1 


-1.05 


1917 


9-7 


8.7 


.279 


3.3 


1.65 


Selection 119: 












1915 


8.8 


7.6 


.231 


4.0 


2.00 




9.8 


8.9 


•354 


7-1 


3-55 


1917 


9.9 


8.4 


.330 


16.7 


8.35 


Selection 133: 












1912 


7-3 


6.6 


.063 


4-3 


2.15 


1913 


7.5 


6.7 


.381 


10.2 


5-10 


1914 


7.8 


6.8 


.301 


6.2 


3-10 


Selection 204: 












1916 


8.4 


7-4 


.082 


2.S 


1.20 


1917 


8.7 


7-9 


.068 


I.O 


•50 


1918 


8.3 


7-1 


.276 


5-0 


2.50 



Assuming a minimum yield of 50 bushels per acre. 



The character of number of rows compared with yield shows nine 
negative correlations and seven positive ones. In twelve comparisons 
out of sixteen, the probable error is larger than the correlation 
coefficient. 

In the case of shelling percentage, there are ten negative correla- 
tions and six positive ones, indicating a tendency toward higher 
yields for ears with low shelling percentage. 



234 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



CONCLUSIONS. 

There seems to be no special relation between number of rows and 
yield, or between shelling percentage and yield. The characters of 
length and weight of ears show positive correlations with yield, but 
they are not consistently large. The character of length seems to 
be somewhat significant, at least for some of the varieties. 

The results would, on the whole, indicate that there is no well 
marked basis for using ear characters to indicate yield possibilities. 

LITERATURE CITED. 

1. Cunningham, C. C. The relation of ear characters to yield. In Jour. 

Amer. Soc. Agron., v. 8, no. 3, p. 188-196. 1916. 

2. Hutcheson, T. B., and Wolfe, T. K. Relation between yield and ear char- 

acters in corn. In Jour. Amer. Soc. Agron., v. 10, no. 6, p. 250-255. 1918. 

3. Love, H. H. The relation of certain ear characters to yield in corn. In 

Proc. Amer. Breeders' Asso., 7: 29-40. 1912. 

4. Love, H. H., and Wentz, J. B. Correlations between ear characters and 

yield in corn. In Jour. Amer. Soc. Agron., v. 9, no. 7, p. 315-322. 1917. 

5. McCall, a. G., and Wheeler, Clark S. Ear characters not correlated with 

yield in corn. In Jour. Amer. Soc. Agron., v. 5, no. 2, p. 117-118. 1913. 

6. Montgomery, E. G. Experiments with corn. Nebr. Agr. Expt. Bui. 112. 

1909. 

7. Olson, P. J., Bull, C. P., and Hayes, H. K. Ear type selection and yield 

in corn. Minn. Agr. Expt. Bui. 174. 1918. 

8. Pearl, Raymond, and Surface^ Frank M. Experiments in breeding sweet 

corn. In Ann. Rept. Maine Agr. Expt. Sta., p. 249-307. 1910. 

9. Williams, C. G., and Welton, F. A. Corn experiments. Ohio Agr. Expt. 

Sta. Bui. 282. 1915. 



KIESSELBACH : EXPERIMENTAL ERROR. 



EXPERIMENTAL ERROR IN FIELD TRIALS.^ 

T. A. KlESSELBACH. 

In a recent issue of the Journal of the American Society of 
Agronomy, Doctor H. H. Love^ questions certain conclusions of 
mine^ on (i) competition between adjacent test rows as a source of 
experimental error and (2) limitation in the use of the probable 
error calculation. I am indebted to Doctor Love for his criticism 
and am gratified that the majority of my conclusions apparently 
meet with his approval. An explanation of my position may clear 
up some points on which we appear to differ. 

COMPETITION BETWEEN SINGLE ROW TEST PLATS. 

Shade as a factor is row competition between somewhat unlike 
varieties, selections, or rates of planting was not entirely overlooked 
in the bulletin in question. On page 15 of Nebraska Research Bul- 
letin 13 is given an illustration of spring wheat growing adjacent to 
winter wheat as an extreme example of competition, and on page 14, 
line 22, it is stated that the spring wheat was planted to the south of 
the winter wheat. For the sake of brevity it was left to the reader 
to conclude that the matter of shading could in this case not be the 
limiting factor in competition. It is, however, further stated that in 
this case the "complete failure of the first row of spring wheat may 
be accounted for by the shortage of both moisture and available plant 
food material, due to the more rapid and luxuriant growth of the 
adjacent winter wheat. While this is an extreme example of com- 
petition between adjacent rows, it illustrates a principle commonly 
applying in crop yield tests." Some of our competition studies were 
conducted with the rows running north and south and others east 
and west. While we have never made a comparative study of the 

1 Contribution from the Department of Agronomy, Nebraska Agricultural 
Experiment Station, Lincoln, Nebr. Received for publication June 2, 1919. 
This paper is a reply to a criticism by Doctor H. H. Love of Cornell Uni- 
versity of a bulletin by Professor Kiesselbach. Proof of Doctor Love's 
criticism was sent to Professor Kiesselbach, but his reply was not received 
until the issue containing Love's article was in press. 

2 Love, H. H. The experimental error in field trials. In Jour. Amer. Soc. 
Agron. II : 212-216. 191 9. 

2 Kiesselbach, T. A. Studies concerning the elimination of experimental 
error in field trials. Nebr. Agr. Expt. Sta. Research Bui. 13. 1918. 



236 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

exact effect of the direction of the rows we certainly have had strik- 
ing competition, no matter what the direction of the rows. In his 
criticism, Doctor Love appears to assume that shade is the only 
factor in plat competition, overlooking the other more important 
elements. 

Competition studies reported were not confined to rate-of-planting 
tests, but include comparisons between varieties and types as well. 
The same general principles are brought out in each case. 

The rate-of-planting tests with small grain extended over a period 
of two years, 191 3 and 1914, and the results are reported in the 
bulletin in question on pages 15-18. Probably Doctor Love has over- 
looked my statement in the bulletin on pages 18 and 19 regarding the 
exact number of plants in the thick and thin rates of seeding. It is 
true that the rate of planting was not given, but in both table and 
discussion the exact number of plants in 10 feet of row was stated, 
which eliminates the uncertain factor of imperfect germination. 
Furthermore, I have given the exact number of stools, which throws 
additional light on the actual amount of vegetation in each case. 
Perhaps it was an oversight on my part in not connecting Table 3 
more closely with Tables i and 2 by some such means as a footnote 
instead of the simple statement preceding Table 3. It was assumed 
that the careful reader would not fail to see the connection. Table 3 
gives the figures only for 1914, while the statement should have been 
made that planting rates for the two years were as nearly duplicates 
as possible. In the case of the competition rate-of-planting tests with 
corn the exact rate was stated for every trial for every year. In 
order to further clarify the matter of plat competition the paper pub- 
lished elsewhere in this issue* has been prepared. 

Doctor Love's suggestion that the likelihood of error resulting 
from row competition would be reduced by grouping varieties of 
rather similar growth habit together, would without doubt reduce 
such error. However, in the first year of many experiments in which 
unfamiliar crops are tried for the first time, such grouping might 
not be very dependable. Furthermore, it appears that varieties fairly 
similar in growth habit may differ for some reason in relative com- 
petitive quality. 

PROBABLE ERROR. 

A statement of my position regarding the use of the probable error 
would doubtless not be out of place in this connection. 

* Kiesselbach, T. A. Plat competition as a source of error in crop tests. In 
Jour. Amer. Soc. Agron., v. 11, no. 6, p. 242-247. 1919. 



KIESSELBACH : EXPERIMENTAL ERROR. 



1. The probable error has a legitimate use. 

2. It indicates the precision among replicates, but a small probable 
error in no way proves that those replicates may not all vary simi- 
larly due to a methodic or systematic error running thruout the 
series, or to certain accidental groupings. A small probable error 
indicates the absence of serious accidental errors or variations within 
a series of replicates. This is especially true if reasonably large 
numbers are averaged. Its dependability is greatly reduced in case 
of low frequencies. While a small probable error may indicate such 
precision, it does not necessarily indicate reliability, dependability, or 
accuracy as to the inherent intrinsic comparative values sought. 

3. Thru misapplication the probable error may act to cover or sup- 
port data that is worthless or actually misleading because of errors 
that it does not and cannot reveal. 

4. There are two general classes of experimental errors, accidental 
and systematic. In many experiments there may be an intermingling 
of both sorts. Accidental errors are such as distinctly local and 
rather abrupt soil irregularities within the confines of an experi- 
mental field, and irregularities in stand caused by rodents, cutworms, 
etc. Among the systematic variations or errors may be included 
plat competition, where distinct types or planting rates are grown in 
very close proximity as in adjacent rows, and serious soil limitation 
in pot fertilizer experiments, either thru size of pot or thru rate of 
planting. 

A systematic variation may under certain conditions be reflected 
in the probable error and in other cases it may not. This depends 
upon the constancy of the error. A constant or methodic error run- 
ning through a series is not adequately shown in the probable error. 
This is illustrated in the reference to thickness of planting in pots on 
pages 73 and 74 of the bulletin. If one crop is planted thruout the 
experiment at a normal rate and another crop in comparison is 
planted unconsciously at an excessive rate, tho all pots practically 
agree and the probable error is small, the results are not dependable. 

In many pot fertilizer experiments, the crop has been uncon- 
sciously subjected to a serious soil limitation, as is illustrated in 
Tables 39, 40, and 45 of Nebraska Research Bulletin 13. Working 
out the probable error for pots in which the soil is seriously limited, 
either thru size of pot or thru rate of planting, would in no way 
disclose such soil limitation as invalidating the results from the stand- 
point of the values sought. 

If a series of plats are duplicated in the same relative order in a 



238 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

sloping field the variety which falls at the lower end of the series 
each time is likely to be favored thruout by more favorable moisture 
and fertility conditions. If one is aware of such a soil variation the 
planting order of duplicate series may be so rearranged as to over- 
come the systematic variation in large part and thereby more nearly 
restrict the tests to accidental variations. The actual error *would 
thereby likely be diminished without a corresponding decrease and 
with possibly even an increase in the size of the probable error. 
Systematic variation of this sort in crop tests may doubtless be over- 
come in part by check plat corrections. 

5. In general, of itself, probable error indicates little apart from 
other complete description of the experiment showing replication and 
proper extent of the work. Its use is to be encouraged to indicate 
precision only, when the experiment has been planned and carried 
on in a manner agronomically sound. Hiding meager or poorly 
founded data behind a low probable error, which may be done unless 
the methods are adequately stated, would be unscientific. 

Concerning Doctor Love's criticism of my discussion on probable 
error, I am obliged to feel that, in the main. Doctor Love and I are 
agreed but that in my attempt at brevity I failed to make myself 
clearly understood. 

In the first place let us consider the criticism of my analysis of the 
use of the probable error in single row comparative yield tests. 
What is the correct application of this conclusion? For example, 
as a method study two distinct comparative yield tests of two differ- 
ent rates of planting were made under rather similar conditions for 
Turkey winter wheat. One test was made with two planting rates 
in adjacent rows, subject to plat competition as all single row test 
plats are to a greater or less extent. A corresponding test was 
made in larger blocks containing 5 rows of a kind and naturally far 
more free from plat competition. In part of the tests practically all 
effect of plat competition in the blocks was eliminated by discarding 
the border rows. In both experiments, whether tested in rows or in 
blocks, the probable error was relatively small — about 2 percent. 
Had only the single row comparative test been made without the 
block test as a check upon it, and by attaching the usual significance 
to the probable error, one would have concluded that the results in 
the row tests were very reliable as indicating the intrinsic relative 
productivity of the two rates. Now that is exactly what is likely 
to happen with the extensively used single row comparative yield test 
plats. Nebraska as well as Cornell and many other stations have 



KIESSELBACH : EXPERIMENTAL ERROR. 



repeatedly used the single row test plat, especially in grain breeding 
work, rather unconscious of the magnitude of the experimental error 
often resulting from plat competition. What I had in mind in the 
bulletin was to bring out the fact that one might work out the prob- 
able errors for the comparative yields obtained in single test rows, 
concluding from small probable errors that the results were reliable 
and dependable as to inherent productivity, whereas the hidden, un- 
recognized error of competition might have resulted in very faulty 
data and erroneous conclusions. 

At the Nebraska station, we have not used the single row plat 
during the past five years except in method studies. The Minnesota 
station has also recently concluded that competition is likely to invali- 
date results from single rows. Of course, during the first year in 
certain crop improvement work, before a sufficient supply of seed is 
available, it may be necessary to use single rows, but one cannot 
place much confidence in these preliminary results. 

In Volume 2 of the Proceedings of the American Society of 
Agronomy, ° a plan is outlined for testing, in single rows, light and 
heavy kernels in cereals. The experiments call for rather striking 
differences in planting rates. Anyone conducting such a test might 
work out the probable error for the ten replications and conclude 
from the small probable error which is almost certain to result that 
the data are reliable. In fact, however, the yields would be apt to be 
subject to striking plat competition as I have described and the results 
be not only unreliable but very misleading. I am calling attention to 
this article only for the sake of illustrating the fact that our entire 
experimental procedure is a matter of evolution of methods and 
many unconscious errors have been committed which the competition 
studies reported in my bulletin indicate. 

One purpose in presenting the data for 200 thirtieth-acre oat plats 
arranged into 50 groups of 4 adjacent plats was to show that an 
apparently uniform field may be very heterogeneous, and that it 
would be a great fallacy to plant, as has occasionally been done, a 
number of adjacent duplicate plats and attach much significance to 
the mean results. In this particular case such a procedure would 
seem absurd since the heterogeniety of the field is made so evident 
by virtue of the entire field having been planted to a single variety 
of oats. However, had this been an actual test of 50 varieties in 4 
adjacent duplicate plats, the absurdity would not have been so evi- 

5 Montgomery, E. G. Methods of testing the seed value of light and heavy 
kernels in cereals. In Proc. Amer. Soc. Agron., 2 (1910) : 59-69. 191 1. 



240 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

dent. I state in the discussion criticised by Doctor Love that the 
experiment " shows that a uniform appearing field may be so hetero- 
geneous in soil conditions that its mean yield cannot be regarded as 
correctly representing the true value of its various parts." Attaching 
significance to probable error calculations of this sort would be a 
fallacy. It would be a misapplication rather than a shortcoming of 
probable error. 

With reference to Doctor Love's criticism on page 213, let us 
assume that instead of these 50 groups of 4 adjacent plats all planted 
to one variety, we have fifty distinct varieties. In such a case the 
probable error calculation for the extreme variation of 21.5 h= 2.55 
bushels would not be evidence that the grouping of 4 adjacent plats 
is at fault, but if used at all it would probably be used to indicate an 
actual intrinsic difference in productivity. The probable error used 
in a varietal test such as this would not throw light upon the inac- 
curacies of the methods, the opinions of some investigators notwith- 
standing. I may state that I have also called attention in the bulletin 
to the greater reliability of systematically replicated plats than of 
adjacent duplicate plats. I have further stated that " an applica- 
tion of the probable error to these systematically distributed plats 
would seem fairly reasonable." 

In my discussion of the probable error in the bulletin, I undertook 
rather to point out cases where the probable error would not apply 
and would in fact lead to erroneous conclusions in certain cases, than 
to eulogize the probable error and set forth its possibilities. Our 
experimental work along this line was more by way of elimination. 

We feel very confident that care must be exercised in applying the 
probable error interpretation to experiments greatly subject to sys- 
tematic errors in order that unwarranted confidence in the results be 
not thereby engendered. Furthermore, its use in connection with 
means of very low frequency is of very doubtful value in crop tests. 
It was not my intention to condemn the use of the probable error 
altogether, but rather to set forth certain cases of misapplication. 

I wish to attempt to clarify one further example given in the 
bulletin which I fear I may not have made quite clear. This occurs 
in the bulletin under the heading, Water requirements of corn and 
wheat." It seems self evident in the case I have given that the 
probable error interpretation will not apply in the water requirements 
of wheat planted at the normal field rate and corn planted at 6 
times the normal rate. However, if such a test were conducted, as 
has been done many times by various investigators, quite unawares 



KIESSELBACH : EXPERIMENTAL ERROR. 



241 



of the discrepancy in relative planting rates, the absurdity would not 
be so evident and perhaps not at all apparent. There are a number 
of instances where this identical oversight in planting rate in past 
experiments has occurred and in the published results, small prob- 
able errors are given as evidence of the reliability of the experiment. 

I am aware that there are several formulas for working out the 
probable error. I had thought it of little importance which I used 
in this purely theoretical discussion of principles. Somewhat dif- 
ferent results are obtained in the size of the probable error, accord- 
ing to the formula used, but this would not seem materially to affect 
the general conclusions regarding the basic principles in the use of 
the probable error. I merely selected the formula given by Daven- 
port (Principles of Breeding, 1907 ed., p. 440) for the reason that 
other parts of my discussion were also based upon his work. 

I realize that a critical search into the actual significance of the 
probable error as applied to crop experiments is almost pioneer work. 
In this pioneer work one is apt to offer suggestions and interpreta- 
tions which justify criticism. The ultimate result will, however, be 
wholesome if it provokes further inquiry looking toward a correct 
solution. Certainly the suppression of such inquiry would be 
undesirable. 

Dr. Love asks the question, Shall we refuse to use the probable 
error because it points out inaccuracies in our methods ? " May I in 
turn ask Doctor Love if we shall recommend without qualifications 
the indiscriminate use of the probable error when without question 
it acts in many cases to give credence to very faulty results? Shall 
we leave unmodified the very common understanding that by " giv- 
ing the probable error along with any result, the reader may know 
what degree of confidence is to be placed in the results " ? 



242 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



PLAT COMPETITION AS A SOURCE OF ERROR IN 
CROP TESTS.i 

T. A. KlESSELBACH. 
INTRODUCTION. 

That a rather keen competition for soil moisture and nutrients is 
likely to exist between plants differing in growth habit when grown 
in close proximity is a well recognized principle in ecology. In- 
vestigations conducted at the Nebraska Agricultural Experiment 
Station indicate that this element of competition is a greater source 
of experimental error in crop tests than is commonly appreciated. 
This source of error occurs most extensively in small grain nursery 
row tests and in i-row or 2-row corn test plats, in which two sorts 
are grown side by side. Its most exaggerated case is, perhaps, the 
testing within a single hill of several corn types differing markedly 
in growth characteristics. 

Errors resulting from such plat competition appear to be fully as 
pronounced in many cases as are the errors resulting from soil and 
other environmental variations, remedies for which have long been 
sought in the use of check plats and in replication. This effect of 
competition is a hidden error which cannot be corrected and should 
be avoided by supplying proper experimental conditions. 

The general conclusion relative to comparative yield tests to be 
drawn from these investigations is that any crop being tested should 
be surrounded by a crop of its own kind in order to avoid the effect 
of competition with a dissimilar crop, for moisture, nutrients, and 
possibly light. 

The principles brought out in these tests concerning plat competi- 
tion should be applicable to any yield test in which dissimilar crops 
are being compared. This may be accomplished for all practical 
purposes by substituting plats containing three or more rows for 
single row plats and then discarding from the yield test the outer 
rows which are subject to competition with the adjoining plats. In 
case of wide field plats, discarding the outer rows is not so important 
since the percentage error for the entire plat caused by competition 
would be much lower. The degree of error resulting from such 

1 Contribution from the Department of Agronomy, Nebraska Agricultural 
Experiment Station, Lincoln, Nebr. Received for publication June 2, 1919. 



KIESSELBACH : PLANT COMPETITION. 



competition will depend primarily upon the extent to which the crops 
being tested differ in their vegetative characteristics. The competi- 
tion will also vary in different seasons. 

The following investigations were made for the purpose of de- 
termining the extent to which plat competition is a factor in crop 
yield tests. In these experiments the relative yields of the crops 
compared in well replicated blocks containing 5 rows for small grain 
and 3 rows for corn were regarded as the true relative values for the 
particular crops. Any difference in their relative yields when grown 
in single adjacent rows may be ascribed to plat competition. In the 
more recent tests the outside rows of blocks have been discarded 
and the true relative yields, practically free from competition, based 
upon the remaining rows. The small grain plats have been repli- 
cated 50 times and the corn plats 8 or more times in these tests in 
order to eliminate the accidental mechanical and physical errors due 
to variation in soil, exposure, stand, etc. 

SMALL GRAIN RATE-OF-PLANTING TESTS. 

During two years, Turkey winter wheat was sown in both alternat- 
ing single row nursery plats and in alternating 5-row nursery plats 
at two distinct planting rates, 2 and 5 pecks per acre. The rows were 
16 feet long and 10 inches apart. In 1913 the thin rate yielded 90 



Table i. — Relative yields of two rates of seeding Turkey wheat and Kherson 
oats when compared in alternating rows and in alternating 5-row plats. 

TURKEY WHEAT. 



Year and rate of seeding. 


Average yield of 50 plants. 


Alternating single rows. 


Alternating 5-row blocks." 




Grams. 


Percent. 


Grams. 


Percent. 


I913: 










Thick rate (5 pk.) 


389 


100 


394 


100 


Thin rate (2 pk.) 


264 


68 


355 


90 


1914: 












327 


100 


251 


100 


Thin rate (2 pk.) 


115 


35 


203 


81 



KHERSON OATS. 



I9I3: 










Thick rate (8 pk.) 


233 


100 


222 


100 




148 


64 


178 


80 


1914: 










Thick rate (8 pk.) 


220 


100 


202 


100 


Thin rate (4 pk.) 


148 


67 


207 


102 



° Yields based on 3 inner rows of 5-row plats in 1914. 



244 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

percent as much as the thick rate in blocks, and only 68 percent as 
much in competing single row plats. In 1914 the thin rate yielded 
81 percent as much as the thick rate in blocks and only 35 percent as 
much in competing rows. The thin rate is seen to have been at a 
decided disadvantage when grown in rows adjacent to the thick rate. 

In a similar test in 191 3 with Kherson oats, the thin rate (4 pecks 
per acre) yielded 80 percent as much as the thick rate (8 pecks per 
acre) in blocks, and only 64 percent as much in competing single row 
plats. In 1914 the thin rate yielded 2 percent more than the thick 
rate when compared in 5-row blocks, while in competing single rows 
it yielded 33 percent less. 

SMALL GRAIN VARIETAL TESTS. 

Two varieties of winter wheat, Turkey and Big Frame, were com- 
pared during 1913 and 1914 in both alternating single-row nursery 
plats and in alternating 5-row plats, sown at the rate of 5 pecks 
per acre. In 191 3 the Big Frame wheat yielded 3 percent less than 
the Turkey when grown in 5-row blocks, whereas in competing 
single rows it yielded 7 percent more. In 1914, the Big Frame again 
yielded 3 percent less than the Turkey in 5-row blocks, while in 
single competing rows it yielded 15 percent less. In a similar test 
between Turkey and Nebraska No. 28 wheat both varieties yielded 
relatively the same whether in rows or blocks in 191 3, the Nebraska 
No. 28 yielding 7 percent more in each case. However, in 1914, the 
Nebraska No. 28 yielded 15 percent less than the Turkey in the 
blocks, and 37 percent less in the competing rows. 

The relative competitive qualities of two varieties or selections 
may reverse in different seasons according to climatic conditions, 
as seen in both the above wheat varietal tests and the following oat 
varietal tests. 

Kherson and Burt oats sown at the rate of 8 pecks per acre were 
compared in alternating rows and blocks during two years. In 191 3, 
the Burt yielded 12 percent more than the Kherson when grown in 
5-row plats and 30 percent more in alternating single rows. In 
1914, the Burt yielded i percent more than the Kherson in blocks 
and 39 percent more in competing rows. 

Kherson and Swedish Select oats were compared likewise in rows 
and blocks, at the rate of 8 pecks per acre. In 1913, the Swedish 
Select yielded 23 percent less in blocks and 18 percent less in compet- 
ing rows than the Kherson. The following year, Swedish Select 
yielded 7 percent less than Kherson in blocks and 11 peircent less in 
competing rows. 



KIESSELBACH : PLANT COMPETITION. 



245 



The data on these tests are given in Table 2. 

Table 2. — Relative yields of two small grain varieties when compared in alter- 
nating rows and in alternating 5-row plats. 



WHEAT. 







Average yield of 50 plats. 














Year a,nd variety. 












Alternating single rows. 


Alternating 5-row blocks." 




Grams. 


Percent. 


Grams. 


Percent. 


1913: 










Turkev 


325 


100 


408 


100 


Big Frame 


347 


107 


397 


97 


1914: 










Turkev 


342 


100 


320 


100 


Big Frame 


290 


85 


310 


97 


1913: 










Turkey 


365 


100 


396 


100 


Nebr. No. 28 


390 


107 


423 


107 


1914: 










Turkey 


369 


100 


334 


100 


Nebr. No. 28 


232 


63 


285 


85 


OATS. 


I913: 












201 


100 


209 


100 


Burt 


261 


130 


234 


112 


1914: 










Kherson 


152 


100 


204 


100 


Burt 


211 


139 


207 


lOI ' 


1913: 










Kherson 


192 


100 


191 


100 




157 


82 


147 


77 


1914: 










Kherson 


205 


100 


219 


100 


Swedish Select 


182 


89 


204 


93 



'^Yields based on 3 inner rows of 5-row plats in 1914. 



CORN RATE-OF-PLANTING TESTS. 

Nebraska White Prize corn was grown for 3 years at the rates 
of 2 and 4 plants per hill in both alternating rows and alternating 3- 
row plats. In the latter case the two outer rows were discarded. 
The corn was checked in rows 72 hills long, 42 inches apart. It was 
planted thick and later thinned to the desired rate. The yields were 
based upon 59 hills in each row containing and surrounded by the 
desired stand. 

In 1914, the 2-plant rate yielded 16 percent more than the 4-plant 
rate in blocks and 18 percent less in competing rows. In 191 5, the 
2-plant rate yielded 31 percent less than the 4-plant rate in blocks, 



246 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

and 37 percent less in competing rows. In 191 6, the 2-plant rate 
yielded 7 percent less t'lan the 4-plant rate in adjacent 1: locks and 22 
percent less in competing rows. 

The data are given i 1 detail in Table 3. 



Table 3. — Relative yields of Nebraska White Pri^e corn from two rates of 
planting when compared in alternating rows and in alternating s-row plats. 



Year and rate of planting. 


Yield per acre." 


Alternating single rows. 


Alternating 3-row blocks, & 




Bushels. 


Percent. 


Bushels. 


Percent. 


1914: 










Four plants per hill 


43-8 


100 


38.4 


100 


Two plants per hill 


35-6 


82 


44-3 


116 


1915: 










Four plants per hill 


101.7 


100 


90.0 


100 


Two plants per hill 


64.2 


63 


62.0 


69 


1916: 










Four plants per hill 


52.7 


100 


51.8 


100 


Two plants per hill 


41-5 


78 


48.6 


93 



« Yields are averages from 8 plats, except that 15 alternating single rows and 
9 alternating 3-row blocks were averaged in 1914. 
^ Yield from the center row of the 3-row block. 



CORN VARIETAL TESTS. 

Plats similar to those just described in the rate-of-planting tests 
were used in the corn varietal tests. In addition to being compared 
in alternating rows and blocks, two varieties of corn were also grown 
within the same hill and their yields compared. 

When compared in blocks, rows, and within the same hill, Pride 
of the North yielded respectively 85 percent, 68 percent and 47 per- 
cent as much as did Hogue Yellow Dent corn in 191 2. A similar 
test in 191 3 was not harvested because of an almost complete corn 
failure, due to drouth. In 1914, the yield of Pride of the North was 
53 percent of that of Hogue Yellow Dent in blocks, 38 percent in 
rows, and 28 percent in the same hill. 

A selfed strain of Hogue Yellow Dent corn which had been greatly 
reduced in vigor was compared in a similar test in 1916 with an 
hybrid of two selfed strains of the same variety. In blocks the in- 
bred corn yielded 37 percent, in competing rows 31 percent, and 
within the sarne hill 21 percent as much as the crossbred corn. 

The data on these tests are given in Table 4. 



i 

•"1 

■I 




I 



HENDRY : ADAPTATIONS OF TEPARV BEAN. 



247 



Table 4. — Relative yields of two corn varieties when compared in alternating 
rows, in alternating 3-row plats, and within the same hill. 



YcAr And Vciricty, 


Alternating 3-row 
blocks." 


Yield per acre. 

Alternating 
single rows.* 


Planted in same 
hill.c 


Bushels. 


Percent. 


BushelsJ Percent. 


Bushels. 


Percent 


10 1 ^ • 














Hogue Vellow Dent 


38.4 


100 


50-8 


100 


26.2 


100 


Pride of the North 


32.9 


85 


33-7 


66 


12.2 


47 


1914: 














Hogue Yellow Dent 


63.1 


100 


77.8 


100 


36.9 


100 


Pride "of the North 


33.7 


S3 


29.2 


38 


10.6 


28 


1915: 














Hogue Yellow Dent 


65-8 


100 


68.3 


100 


30.4 


100 


University No. 3 


64.7 


98 


61.0 


90 


30.0 


99 


1916: 














Fi hybrid of Hogue Yellow Dent inbred 














strains 


76.2 


100 


90.5 


100 


54-0 


100 




28.1 


37 


28.0 


31 


II-3 


21 



° Yields based on center row of 3-row plats in 1914 and 1916. Yields are 
averages from 10 plats except in 1916, when only 9 plats were averaged. There 
were 3 plants per hill except in 1916, when 4 plants per hill were grown. 

^ Yields are averages from 20 plats except in 1916, when only 6 plats were 
averaged. There were 3 plants per hill except in 1916, when 4 plants per hill 
were grown. 

^ One plant of each variety in the hill except in 1916, when two plants of each 
were grown in each hill. Yields are averages from 1,000 hills except in 1916, 
when yields of 300 hills were averaged. 



CLIMATIC ADAPTATIONS OF THE WHITE TEPARY BEAN/ 

G. W. Hendry. 



INTRODUCTION. 



The singularly perfect adaptation of the Tepa'i-y bean to arid 
climates v^as first commented upon by the Arizona Agricultural Ex- 
periment Station in 1912.^ Since that time this bean has become 
an important field crop thruout the arid southwest, and has extended 
its range well into the interior valleys of California, where no less 
than 17,000 acres were devoted to its production in 191 8. 

During five years of field experimentation with this new crop at 
the several California substations, it has become increasingly evident 



i 



1 Contribution from the Division of Agronomy, College of Agriculture, Uni- 
versity of California, Berkeley, Cal. Received for publication March 14, 1919. 

2 Freeman, G. F. Southwestern beans and teparies. Ariz. Agr. Expt. Sta. 
Bui. 68. 1912. 



248 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

that the Tepary bean has certain specific climatic requirements in the 
absence of which it does not thrive. This paper treats of the rela- 
tion of the white Tepary bean (Phaseolus acutifolius A. Gray var. 
latifolius Freeman) to its climatic environment and especially of its 
peculiar reaction to the cool coast climates of central and of northern 
California. 

RELATION OF CLIMATE TO VEGETATIVE DEVELOPMENT. 

Normal Tepary plants grown in the semiarid interior districts of 
California acquire an open trailing habit and may, under favorable 
circumstances, attain a total length of 50 or more inches ; but those 
grown in the cooler coast climates north of Point Conception de- 
velop abnormally. The plants assume a dwarfed, compact, bush 
habit, are devoid of runners, and rarely exceed 20 inches in length. 
The leaflets become smaller, thicker, and develop a crumpled tex- 
ture. The pods are produced sparingly, become shorter and broader, 
and contain fewer seeds. The seeds take on a characteristic grayish 
white color, absorb sufficient atmospheric moisture to become slightly 
enlarged, and frequently germinate feebly in the pods prior to the 
ripening of the vines. The life period is prolonged indeterminately, 
and the foliage continues green until destroyed by frost. Typical 
plants grown in the two environments are shown in Plate 8. 

COMPARATIVE YIELDS FOR SEMIARID INTERIOR CALIFORNIA. 

Varietal trials with beans including Teparies have been conducted 
at three University of California substations situated at Davis, 
Fresno, and Riverside, representative of the interior portions of 
northern, central and southern California respectively. The figures 
in Table i are compiled from the data obtained and show clearly the 
greater prolificacy of the Tepary at these places. 



Table i, — Comparative yields of White Tepary and Pink beans at semiarid 

interior stations. 







Average yield per acre in pounds. 


Locality. 


Number of years. 






White Tepary. 


Pink. 


Davis 


3 


815 


470 


Fresno 


2 


3.005 


322" 


Riverside 


I 


3.159 


683 



° One year only. 



HENDRY : ADAPTATIONS OF TEPARY BEAN. 



249 



These data, decisive as they are, merely confirm a wide experience, 
all of which testifies to the excellence of the Tepary as an arid climate 
crop. The Pink bean, Phascohis vulgaris, here employed as a check, 
is the best known and most extensively cultivated variety in the 
southwest, where it has few equals within the species in point of 
yield. Under very trying conditions of heat and aridity, however, 
such as prevail during the summer months in the localities of these 
experiments, the Pink is greatly reduced in prolificacy and compares 
unfavorably with the more drouth-tolerant Tepary. 

COMPARATIVE YIELDS FOR SUBHUMID COASTAL CALIFORNIA. 

While evincing high merit with respect to yield in the interior dis- 
tricts, the Tepary has made a decidedly unfavorable impression in the 
coast regions, as is shown by the yield data (one year only) in 
Table 2. 

Table 2. — Comparative yields of White Tepary and Pink beans at subhumid 

coast stations. 

Yield per acre in pounds. 
Locality. White Tepary. Pink. 

Berkeley 1,244 1,512 

Santa Cruz o 562 

Smith River 155 683 

At Santa Cruz, representing the south central coast region, at 
Berkeley, representing the central coast region, and at Smith River, 
near the Oregon line, representing the extreme northern coast region, 
the yield relationship with the Pink has been reversed. Moreover, 
in these localities the Tepary has been exceeded in yield by numerous 
other Phaseolus vulgaris varieties. The yield of 1,244 pounds per 
acre obtained at Berkeley is relatively high, but was secured under 
artificial conditions, in that the crop was cured and thrashed by hand, 
indoors. Had usual field methods been employed, the crop could 
not have been saved from the rains and the yield would have been 
virtually nothing. 

These tests, together with numerous other observations in the field, 
have clearly shown the climatic limitations of the Tepary, and have 
proved it to be imperfectly adapted to the cool coast regions of 
central and of northern California. 

THE RELATIONSHIP OF CLIMATE AND PLANTING DATE TO THE PRE-BLOSSOMING PERIOD. 

The interval from planting to the complete opening of the first 
blossoms, here designated as the pre-blossoming period, has been 



250 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



found to be a function of climate, and to vary with the locality and 
atmospheric temperatures subsequent to planting. It has been 
longest in cool climates and has been increased or diminished as the 
planting date has caused its occurrence during cool or warm weather. 
Observations upon these relationships follow in Table 3. 



Table 3. — The relation of locality and planting date to the pre-hlossoming 
period of Tepary beans. 



Berkeley. 


Davis. 


Planting date. 


Pre-blossoming 
period in days. 


Planting date. 


Pre-blossoming 
period in days. 




80 
78 
77 


April 13 


91 

51 
42 


May 17 


May 30 


July 2 


July 5 






Average 


78 




61 



At Berkeley the average pre-blossoming period was 78 days, while 
the corresponding average for the warmer climate of Davis was 61 
days. The fact that the early planting at Davis required 91 days 
to blossom, a longer period than for any other planting either at 
Berkeley or Davis, is due to the circumstance that this planting was 
made eighteen days earlier than the earliest Berkeley planting, and 
was followed by a period during which exceptionally low tempera- 
tures prevailed. In the three months immediately following this 
planting the minimum temperatures were 31°, 37° and 41° F., while 
the corresponding temperatures for the months following the first 
planting at Berkeley were 41°, 44°, and 51° F. On the other hand, 
the mean temperatures for the summer months immediately follow- 
ing the second and third plantings at Davis averaged from 10° to 
15° F. above the corresponding temperatures at Berkeley, resulting 
in short pre-blossoming periods of 51 and 42 days respectively, com- 
pared with 78 and 77 days for the cooler climate of Berkeley. 



Table 4. — Mean temperatures for Berkeley and Davis, Cal., by months from 
April to December igiy". 



Month. 



Mean temperature (°F.). 


Month. 


Mean temperature (°F.). 


Berkeley. 


Davis. 


Berkeley. 


Davis. 


55.6 


57.6 


September 


66.1 


71.6 


55-4 


60.2 


October 


63.0 


66.8 


62.0 


73-2 


November 


57.6 


53-7 


63.2 


78.7 


December 


54-8 


48.0 


60.2 


75-0 









April . . 
May. . 
June . . 
July. .. 
August 



« Beals, E. A. In Ann. Climat. Rpt., Cal. Sect. 1918. 



HENDRY : ADArTATIOXS OF TEPARY BEAN. 



251 



THE RELATION OF CLIMATE AND PLANTING DATE TO THE BLOSSOMING PERIOD. 

It has also been ascertained that the interval from the complete 
opening of the first blossom to the falling of the last blossom (here 
referred to as the blossoming period) is also a function of climate, 
that it is longer in cool climates than in warm climates, and that it is 
either increased or diminished in any locality as the planting date 
causes it to occur during cool or warm weather. Some observations 
upon these relationships appear in Table 5. 



Table 5. — The relation of locality and planting date to the blossoming period. 



Berkeley. 


Davis. 


Planting date. 


Blossoming period 
in days. 


Planting date. 


Blossoming period 
in days. 


May I 


57 
35 
74 


April 13 


44 
35 
35 




May 30 


July 2 


July 5 






Average 


55 


Average 


38 



The average blossoming period for the three Berkeley plantings 
was 55 days, while the corresponding average for the warmer climate 
of Davis was 38 days. The effect of planting date upon the blossom- 
ing period and the correlation between the blossoming period and 
mean temperatures are here well illustrated. The blossoming period 
for the second planting at Berkeley was only 35 days compared to 
57 days and 74 days, respectively, for the first and third plantings, 
and since the blossoming period of this second planting occurred 
during the highest prevailing temperatures (Table 4), its brevity is 
in harmony with the relationship Dreviously noted. 

The second and third Davis plantings caused the blossoming 
periods to occur during the intense heat of July and August (Table 
4), in consequence of which very short blossoming periods of 35 
days each resulted. The blossoming period of the first Davis plant- 
ing, on the other hand, occurred during cooler weather, in conse- 
quence of which it was lengthened to 44 days, and doubtless it would 
have been still longer had not the long pre-blossoming period of 91 
days caused it to occur so late in the season. 

THE RELATION OF CLIMATE AND PLANTING DATE TO THE LIFE PERIOD. 

The life period is here regarded as the time elapsing from the 
planting of the seed to the complete ripening of the plants. Since 
its duration is in part determined by both the pre-blossoming and the 



252 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

blossoming periods, it varies as they do and is governed by the same 
influences. Some observations upon its relation to climatic varia- 
tions are shown in Table 6. 



Table 6. — The relation of locality and planting date to the life period. 



Berkeley. 


Davis. 


Planting date. 


Life period in days. 


Planting date. 


Life period in days. 


May I 


157 
135 
l66« + 


April 13 


148 
96 
92 




May 30 


July 2 


July 5 








153 + 


Average 


112 



"Killed by frost in December prior to maturity. 



The average life period for Berkeley was 153 + days, while for 
Davis it was 112 days, again illustrating the relationship between 
temperature and period of development. The third Berkeley plant- 
ing resulted in the development of the plants during cool autumn 
weather (Table 4), in consequence of which these plants had shown 
no indications of ripening previous to their destruction by frost, 166 
days subsequent to planting. It was in this planting that the abnor- 
mal vegetative development previously described was most apparent. 

The first Davis planting matured in 148 days, the second in 96 
days, and the third in 92 days, and as the mean temperatures for 
these periods vary inversely as the corresponding durations (Table 
4), the observations are in harmony with the relationships as previ- 
ously stated. 

SUMMARY. 

Tepary beans grown in the cool climates of the central and northern 
California coast districts develop abnormally. 

The White Tepary is more prolific than varieties of Phaseolus 
vulgaris in the semiarid interior districts of California. 

The White Tepary is less prolific than varieties of Phaseolus vul- 
garis in the subhumid coast districts of central and northern 
California. 

The pre-blossoming period, the blossoming period, and the life 
period are each functions of climate. They are longer in cool 
climates than in warm climates, and they are either increased or 
diminished as the planting date causes them to occur during cool 
or warm weather. 



karraker: laboratory work in soils. 



253 



WHAT IS THE VALUE OF THE USUAL LABORATORY WORK 
GIVEN IN GENERAL SOILS COURSES 

P. E. Karraker. 

In connection with a study of the soils courses outlined in the 
catalogs of a number of the State agricultural colleges, attention has 
been directed to the nature and value of the usual laboratory work 
given as a part of the first or general soils courses. There is no 
question as to the value of this work to the small number of men 
who will later specialize in investigational or teaching work in soils 
or very closely related lines. It must be kept in mind, however, that 
these are required courses in most colleges, and even where they 
are not, are taken by practically all men finishing undergraduate 
work. There is a question, it would seem, as to the value of this 
work compared with other courses which might be taken, to the 
large number of men who will not thus later specialize. 

Only a very small part of the laboratory work in soils is that in 
which the average student is gaining a knowledge and something of 
the art of doing operations which he will be using in post-gradu- 
ation activity. In this respect the soils work differs from the labora- 
tory work in such courses as stock- judging, farm mechanics, and the 
first courses in dairy husbandry and in horticulture, in that here the 
student is going thru operations which will be common to his post- 
graduation activity and with which previous to his class work he was 
more or less unfamiliar ; and it is in this relation to post-graduation 
activity that the value of these courses must be mainly found. 
Laboratory work in soils to be of a similar nature in this respect 
would have to include such practices as the plowing and preparation 
of land, the application of fertilizers, etc. It is obvious why work 
of this nature is not given. It is either not adaptable to laboratory 
conditions, or else constitutes such a common part of farm practice 
that students are familiar with it before entering college. 

From the standpoint of mental discipline, the usual laboratory 
work in connection with soils courses takes at least equal rank with 
that given in connection with other courses in agriculture, but this 
qualification alone does not constitute a justification for the work. 
From this standpoint alone not only this work but most of the courses 

1 Contribution from the Department of Agronomy, University of Kentucky, 
Lexington, Ky. Received for publication April 18^ 1919. 



2 54 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

in technical agriculture could not be justified when compared with 
certain more exact fundamental courses in liberal arts and natural 
science. 

Let us consider more in detail the laboratory work usually given 
in connection with the introductory or general course in soil physics. 
What is the value to the average student, for instance, of determin- 
ing that air-dry soils contain a certain amount of hygroscopic mois- 
ture, that these soils suffer a certain loss on ignition, that soil samples 
from the field contain so much capillary moisture, that the apparent 
and real specific gravities of stock soils are so much? Does the 
value, i. e., a justifiable value, come from the operations involved in 
securing these results? It would not seem so, but if it is here could 
it not better be secured in the more accurately controlled laboratory 
work in courses such as those in chemistry and physics? Or is the 
value to be found in the more firm fixing in the mind of the student 
of the facts in question than results from the study of the printed 
page alone ? Again it would not seem so. Is it not open to question 
whether either the nature of the facts themselves or the gain in 
vividness from this manner of their presentation justifies the work*? 

Further, the results from a number of the practices usually given 
are apt to be misleading to the student. The usual determination in • 
the laboratory of the capacity of soils for capillary water gives 
considerably higher results than obtain under field conditions. Re- 
sults from the practices with air and percolation movement of water 
thru soil unless restricted to work with various grades of sand, are 
dependent more on the fineness of grinding of the stock soils than on 
their texture. Clay soils which resist fine grinding usually show 
greater freedom both of air and water movement than the coarse- 
textured soils. There is a tendency for the practice showing capil- 
lary movement of water up into air-dry soils to give to students the 
idea that the soil with greatest capillary movement is the most de- 
sirable from the moisture standpoint. The important thing under 
field conditions, however, is moisture retention and not moisture 
movement and one very important factor making for moisture reten- 
tion, the content of organic matter, works against extent of capil- 
lary movement in the practice in the laboratory. A marked example 
of a misleading laboratory practice is that showing the effect of 
mulches in saving moisture when but a short distance above a water 
table. In all these practices it is necessary for the instructor to ex- 
plain very clearly that the conditions under which the results are 
secured are not comparable to field conditions and therefore the 
results themselves are of but limited application. 



karraker: laboratory work in soils. 



255 



The practices referred to in the preceding two paragraphs do not 
include all the work usually given and some of the work is not thus 
open to question. Unfortunately, however, the great important 
processes concerned in the making of the earth's surface a suitable 
place for the growth of crops, such as the change of rock into soil, 
the building up of the soil organic matter and nitrogen content, the 
production of good structural conditions, movement and control of 
water' and air under field conditions, and the way crops feed either 
can not be reproduced accurately or else can not be reproduced at all 
by the student in the laboratory, especially the student in the first 
course. 

An additional and a different reason for the need of attention to 
the laboratory work usually given in general soil physics courses is 
that already some of this work has been and in the future an increas- 
ing part of this work will have been done by the students in agri- 
cultural courses in secondary schools previous to entering universities. 

The laboratory work in the usual first or general course in soil 
fertility, even more than that in soil physics, finds its declared value 
m.ainly in the analytical results secured. A large part of such work 
is the determination of nitrogen and phosphorus and less often of 
potassium in farm products, manures, fertilizers, and soils. Prac- 
tices may also be included showing nitrification, fixation of bases, 
etc., but such practices are not on the whole well adapted to labora- 
tory work in these courses. 

The average student does the laboratory work in soil fertility with 
interest, but again the question arises as to the particular way in 
which this w^ork is of justifiable value. Is the value in a more 
definite knowledge on the part of the student of the fact, for in- 
stance, that commercial sodium nitrate contains about 15.5 percent of 
nitrogen after having made the determination himself than if secured 
from the printed page alone? It is very doubtful if there is any 
marked gain in definiteness of knowledge in this particular instance 
and those of similar nature thru the laboratory determination. 
Neither would there seem to be any justifiable return to the student 
from the prosecution of the work involved in securing these results. 
Again, as in the case of the soil physics work, if the value is here, 
the course in this respect has no relation to technical agriculture and 
such returns should be secured from the taking of additional work 
in general quantitative analysis. In reality it may be questioned 
whether students should be required to take any work in quantitative 
chemical analysis unless the expectation is that such work or work 



256 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

of a closely related nature will form a part of their post-graduate 
activity. The work in quantitative analysis finds a place in the re- 
quired work in the curricula of agricultural colleges as a prerequisite 
to laboratory work in soil fertility. While recognizing a general 
value of the quantitative analysis work, yet if the need for it as a 
prerequisite for other work did not exist, would it not be a fair ques- 
tion whether students' time could not be better spent for example in 
the taking of further work in general chemistry, an introductory 
course in organic chemistry, or a course in college physics ? 

Greater value, perhaps, attaches to the work with soil, determina- 
tion of nitrogen, phosphorus, potassium, and acidity, provided the 
student works on a soil in which he is interested, such as that from 
his home farm. Here there is an opportunity for the securing of 
original information, but with the knowledge most experiment sta- 
tions have accumulated as to the chemical nature of the soils within 
their State, the results secured by the average student are likely to 
give him but little added information and may even not be as reliable 
as the more general but more accurate data obtained by the station. 

The introductory courses in soil biology are not so often required 
courses. When they are, the laboratory work connected with them 
is open to the same questioning attitude as that in the courses in soil 
physics and fertility. Even when the courses are not required, it 
may be questioned whether the student taking a general course in 
agriculture should not be given a chance to secure the subject matter 
of the courses without the laboratory work. Laboratory work also 
in certain other than the soils courses is likewise open to this same 
questioning attitude; such, for instance, as the laboratory work in 
introductory courses in farm crops and in entomology. 

It has not been the intention in this paper to present conclusions 
but to express doubt as to the justifiable value to the students of the 
usual laboratory work in first or general soils courses as compared 
with other work which might be taken. In particular, it is desired 
to raise the question whether it would not be advisable to give this 
work as separate courses, thus giving opportunity for the securing of 
the subject matter without the laboratory work and requiring the 
latter only of men desiring to specialize in soils or closely related 
work. 



KARPER & CONNER: POLLINATION IN MILO. 



257 



NATURAL CROSS-POLLINATION IN MILO.^ 

R. E. Karper and a. B. Conner. 

An appreciable amount of natural cross-pollination takes place in 
grain sorghum, as is evidenced by the hybrid plants which are con- 
stantly appearing in fields of this crop. These hybrid plants in grain- 
sorghum fields are more readily observable than hybrid plants in 
Indian corn, since the types of grain sorghum are more varied, result- 
ing in more strikingly different hybrids. Very little definite informa- 
tion has been published as to the amount of cross-pollination occur- 
ring in grain sorghum. The extent of natural cross-pollination in 
this crop is of the greatest importance to the plant breeder and to the 
farmer, as both the improvement and the maintenance of purity are 
affected by natural cross-pollination. Information as to the per- 
centage of cross-pollination under natural conditions will be an aid 
to the breeder in attaining higher standards and to the grower of the 
crop in maintaining the purity of any improved strain. 

During the season of 191 7 the writers observed some white milo 
plants which had been mechanically introduced in a plat of yellow 
milo. These plants were flowering simultaneously with the yellow 
milo. Forty-one heads of white milo were selected and planted the 
succeeding year, 1918, in head-row plats, using all seed from each 
head. No record was made of the number of seed to the head or 
even the weight of the head. Germination seemed fair, but final 
counts indicated incomplete germination. From each of these head 
rows, in which most of the plants produced white heads, all the plants 
with yellow seed heads were recorded as well as the total number of 
progeny in each row. The data obtained proved very interesting, 
notwithstanding the preliminary nature of the work. Table i shows 
the total number of plants and the total number of visible hybrids 
produced from each head. 

It is seen from the table that several heads have shown a much 
higher percentage of cross-pollination than others, and that such 
heads invariably have shown about the average number of hybrid 
plants. Examination of the number of progeny from these same 
heads as compared to progeny from other heads shows a relatively 
lower number of progeny plants from these heads which have shown 

^ Contribution from the Texas Agricultural Experiment Station, College 
Station, Texas. Received for publication April 30, 1919. 



258 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table i. — Cross-fertilisation as shown in the progeny of white milo plants 
grown under conditions affording maximum natural cross- 
pollination from yellow milo. 



Head or row 
No.« 


Total number 
of progeny 
plants. 


Number of hybrid 
plants w ith 

yellow 
seed heads. 


Number of hybrid 
plants not 
classified as 
yellow. 


Total number 
of hybrid 
plants. 


Percentage 

of cross 
fertilization . 




330 


1 




10 


3-03 




570 


20 


2 


22 


3-85 


3 


184 


21 




2 1 


1 1 .41 


4 


154 


14 


I 


IS 


9-74 


e 



22- 


zyj 




20 


II. 71 


7 


390 


30 




36 


9.09 


3 


57 


g 








14.03 


9 


162 


1 




T R 

lo 


II . II 


10 


119 


5 




5 


4-20 


1 1 


457 


13 




13 


2.84 


12 


279 


2 1 




21 


7-52 


13 


560 


57 




57 


10. 1 7 


14 


304 


22 




22 


5-72 






18 


7 


25 


35-71 




397 


31 




31 


7.80 


1 


203 










2-95 


19 




3 


u 


9 


2.51 


20 


352 


19 




19 


5-39 


21 


237 


4 




4 


T ^^R 
i .00 


22 


oR T 


1 2 




1 2 


4.27 


23 


48 I 


27 


I 




5-o2 


25 


460 


22 


I 


23 


5.00 


26 


990 


40 




42 


4.24 


27 


40 


5 




5 


10. oO 


30 


509 


1 2 




1 2 


2.35 


31 


316 


28 




28 


8.86 


32 


377 


14 


2 


16 


4.24 


33 


372 


13 




13 


3.49 


34 


205 


16 




16 


7.80 


35 


656 


19 


I 


20 


3-04 


36 


635 


36 


I 


37 


5.82 


37 


153 


26 


2 


28 


18.30 


38 


344 


16 




16 


4-65 


39 


293 


15 




15 


5-II 


40 


1,236 


96 




96 


7.76 


41 


585 


39 


16 


55 


9.40 


All rows 


13.430 


788 


42 


830 


6.18 



^Rows 6, 17, 24, 28 and 29 have been omitted for the reason that only a few 
of the plants came into full head, and hence definite counts were impossible. 



a high percentage of natural crossing. This seems to be the case 
with all heads that show cross-pollination greater than the average 
of 6 percent. The 16 heads showing more than 6 percent cross- 
pollination had a total population of 5,022 plants, or an average of 
314 progeny plants to the head, while the 20 heads showing less than 
6 percent cross-pollination had a total population of 8,409 plants, or 
an average of 420 progeny plants per head. These data show a 



WALDRON : CROSS-FERTILIZATION IN ALFALFA. 



259 



variation in the germinability of the different lots of seed and indi- 
cate a proportionate variation in the percentage of cross-polHnation 
•due to germination accounted for by the probable increased vigor of 
hybrid seeds and their consequent persistence in all lots. 

Of 830 hybrid plants observed in the entire series, 42 heads were 
evidently reversions, or were cross-fertilized by pollen from varie- 
ties other than yellow milo. 

The total progeny of 13,430 plants included 830 first-year hybrids 
or an average of 6 percent cross-fertilization where the plant was 
entirely surrounded by others which might cross-pollinate its flowers. 
If the percentage of the cross-pollination was influenced by germina- 
tion in these particular lots, then the actual percentage of cross- 
pollination would be correspondingly lower. 

From these results it would seem that in actual field practice where 
a pure strain is grown near to and flowering at the same time as 
another field which might contaminate it the amount of crossing in 
the outer rows would undoubtedly not exceed 3 percent, half of the 
rate in this case where the white milo plants were entirely surrounded 
by plants of yellow milo. 

CROSS-FERTILIZATION IN ALFALFA.^ 

L. R. Waldron. 

Accurate and detailed knowledge as to the manner and kind of 
pollination in various farm crops has come to be recognized as basic 
for intelligent and successful breeding operations. The recognition 
of the stability of the genotype, at least within the time limits of 
practical plant breeding, makes it necessary to know as definitely as 
may be the character of any genotype upon which work is being per- 
formed, certainly so far as its zygotic condition is concerned. 

A certain amount of work has been done on the maize plant from 
the above standpoint. With this plant it has been amply determined 
that when the ordinary genotypic condition is subject to self-fertiliza- 
tion the yields are reduced about 50 percent the first year as shown 
by Hayes (2) and a reduction of even two-thirds if the self-fertiliza- 
tion is carried thru several generations is shown by Jones (3). 
Hayes (2) has presented limited data to show the amount of cross- 

1 Contribution from the North Dakota Agricultural Experiment Station, 
Agricultural College, N. Dak. Approved by the Director. Received for pub- 
lication August 14, 1919. 



26o JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

fertilization to which an individual maize plant is subject when sur- 
rounded by individuals sufficiently distinct to show immediate color 
differences in the endosperm. Self-fertilization was certainly less 
than 5 percent. It would be of interest to determine the amount of 
cross-fertilization when the amount of pollination received by the 
test plants was provided equally by the two types of plants under 
trial. In other words, what would be the result if the vicinism were 
balanced rather than unbalanced? 

In alfalfa, conditions of pollination are found differing not only 
from such normally self-fertilized plants as wheat, oats, and barley 
but also from the normally cross-fertilized maize plant. The com- 
plicated alfalfa flower obviously suggests insect pollination and re- 
peated investigations have shown that certain hymenopterous insects 
generally play the major part in pollinating alfalfa. While there is 
little or no argument in regard to this point evidently very few data 
have accumulated as to the amount of cross-fertilization effected by 
insect aid. Oliver (5) has pointed out that when an insect releases 
the tripping mechanism of an alfalfa flower, the stigma, striking the 
ventral surface of the abdomen of the insect, carries with it some of 
the pollen of that flower and also picks up foreign pollen from the 
insect's abdomen provided such pollen is present and properly located. 
As the insect leaves, it carries away some of the pollen of the newly 
visited flower. 

The writer has depollinated many alfalfa stigmas and in this work 
has never failed to find the stigma well covered with pollen when 
released from the keel, however gently such release was brought 
about. Piper et al. (6) have shown that it is not necessary that the 
pollen cells be imbedded in the surface of the stigma or that the 
stigmatic cells be ruptured to insure fertilization, as has been claimed 
by some, and that even the friction of the keel against the stigma 
carrying the pollen is not an essential feature. In the foregoing work 
apparently no check flowers were used, so it was not shown that me- 
chanical irritation of the stigma would have been of no benefit. Good 
fertilization results wxre secured from strictly static conditions. The 
general statement may be made that an alfalfa flower freshly pol- 
linated by an insect is surely self -pollinated and also quite possibly 
cross-pollinated, if the insect has newly come from another alfalfa 
flower. 

Piper et al. (6) have also obtained data on the effect of pollen on 
fertilization secured from various sources. Comparing flowers pol- 
linated by their own pollen with flowers pollinated from flowers of 



WALDRON : CROSS-FERTILIZATION IN ALFALFA. 



261 



the same plant there was no appreciable difference relative to the per- 
centage of flowers bearing pods and a doubtful appreciable difference 
in the number of seeds per pod, of the latter method over the former. 
However, when alfalfa flowers were pollinated, using pollen from 
other plants, an appreciable gain in fertilization was noticed, amount- 
ing to an increase of approximately 50 percent in the percentage of 
flowers producing pods. Their figures indicate that cross-fertiliza- 
tion is more efficient in the production of alfalfa seed than is self- 
fertilization. Further investigationns by them, reported in the same 
paper, indicate that pollen from Medicago falcata is as efficient in 
fertilizing M. sativa as is the pollen from M. sativa. 

The experiment in hand was designed to secure data on the amount 
of cross-fertilization occurring between alfalfa plants. The problem 
is not at all simple and the data presented are admittedly only a first 
step toward a complete answer. The experiment was not planned to 
determine the amount of cross-fertilization in any particular plant 
but rather the amount of cross-fertilization taking place between two 
groups of plants considered as units. In such work an evenly bal- 
anced vicinism would be an important feature. Featuring in this 
would be the relative abundance of flowers in the two groups of 
plants, similar habits of growth, similar flowering periods, similar 
abundance of pollen, etc. If data were to be secured on any consid- 
erable number of plants the mere physical limits of the experiment 
would necessitate such a selection of parents as would allow the 
determination of parentage in the F^ generation. This works out 
nicely when the two parents are Medicago sativa and M. falcata, the 
hybrid being strikingly different in flower color than either parent. 
While this is true, certain characters of these two parents tend to 
make the vicinism unbalanced. The smaller number of flowers (in 
my plants), the more or less prostrate habit of growth, and the com- 
parative scarcity of pollen (according to Westgate, 7) of M. fal- 
cata are perhaps the most important features which tended to unbal- 
ance the vicinism between the two groups. 

PLAN OF EXPERIMENT. 

The stock of Medicago sativa used came from Chas. C. Haas, 
Whitewood, S. Dak. The amount of seed received was small, 
amounting to less than a gram, and was said to have come from a 
white-flowered plant. The seed was extremely light in color for 
alfalfa. The stock of M. falcata was secured from Prof. N. E. 
Hansen, Brookings, S. Dak., as living plants. This is called by Han- 



262 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

sen (i) Semipalatinsk alfalfa. The plants used in my experiment 
came into blossom in 1916 and were known to be the true M. falcata 
type before they became a part of the experiment. 

The plants entering into the experiment were planted in a rectan- 
gular bed 3.5 feet apart in each direction, the plants of the two species 
alternating in each row. The following diagram indicates the relative 
positions of the plants in the plat, x representing the plants of one 
species and o the plants of the other. 

X O X O X 
X O X O X o 
O X O X X 

The four plants nearest any selected plant were of the opposite 
type to the selected plant and the four plants next nearest were of 
the same type. The total number of plants in the plat numbered 117 
but the plants of the outside row were used merely as a protective 
border. The plants were well protected by snow during the winter 
of 1916-1917 so that they presented a good appearance at the opening 
of the 1917 growing season. The season of 191 7 was favorable to 
alfalfa seed production. By June 30, 191 7, the M. sativa was in full 
bloom and ahead of the M. falcata in this respect. The flower color 
of the sativa plants was reasonably uniform and in most cases was a 
purplish lavender and far removed from the "white-flowered" char- 
acter which was ascribed to the parent plant of this seed. No trace 
of variegation in flower color (7) was found in any of the plants. 

On June 30 an apparently average sativa plant carried 218 flower 
clusters and the four adjacent falcata plants had 7, 28, 33, and 35 
clusters, respectively. By August i seed was setting with comparative 
abundance on both types of plants. At this time the number of pods 
was determined on a typical plant of each group. The sativa plant 
had 85 stalks which bore 10,041 pods while the falcata plant had 21 
stalks bearing 5,251 pods. The seed from each plant was harvested 
separately. The comparatively small amount of seed from the fal- 
cata plants was due in some measure to the dehiscence of the pods 
as they ripened. The harvested seed was treated with sulfuric acid 
and planted in flats in the winter of 1918. Some of the falcata seed 
did not germinate well and some of the sativa seedlings were killed 
by damping off but this work as a whole was attended with satis- 
factory results. The seedlings were transplanted once before plant- 
ing in the field. 

A total of 4,350 plants were planted in the field from May 2 to 



WALDRON : CROSS-FERTILIZATION IN ALFALFA. 



263 



7. Cutworms and other causes reduced the stand somewhat in spite 
of the replanting that was done. Plantings were made at distances 
of 30 inches each way. The first flowers appeared during the week 
ending June 27 and notes were taken at intervals of about a week 
from then on. 

In Table i are given data as to the amount of hybridity between 
the two species as determined by the offspring and also the amount of 
seed produced by the parent plants. The offspring of each plant of 
191 7 is considered separately. 

Table i. — Quantity of seed produced by parent plants and percentage of hybridi- 
zation in the Fi plants of Medicago sativa and M. falcata when 
grown together. 



Medicago sativa. 



No. 


Seed pro 
duced by 
parent. 


Plants 


Hybrid 


Percentage 


No. 


Seed pro- 
duced by 
parent. 


Plants 


Hybrid 


Percentage 


bloomed. 


plants. 


of hybrids. 


bloomed. 


plants. 


of hybrids. 




Grams. 










Gravis. 








I 


22.8 


79 




S.06 


50 


4-7 


96 


54 


56.25 


2 


20.1 


7 








51 


1.4 


88 


44 


50.00 


3 


18.4 


73 


5 


6.85 


52 


I.O 


30 


15 


50.00 


4 


20.1 


36 


2 


5.56 


53 


1.4 


41 


24 


58.54 


5 


40.7 


82 


6 


7-32 


55 


3.5 


76 


40 


52.63 


6 


36.9 


79 


9 


11-39 


57 


.9 


56 


13 


23.21 


7 


28.8 


73 


3 


4.11 


59 


1.8 


49 


18 


36.73 


8 


26.0 


82 


5 


6.10 


62 


.9 


27 


7 


2593 


9 


II. 2 


68 


2 


2.94 


63 


2.3 


75 


33 


44.00 


10 


38.1 


96 


4 


4.17 


64 


3-3 


74 


38 


51-35 


II 


18.0 


79 


13 


16.46 


65 


2.9 


44 


17 


38-64 


12 


27.3 


74 


4 


5-41 


66 


7.8 


74 


16 


21.62 


13 


21.7 


76 


3 


3-95 


67 


2.1 


73 


29 


39-73 


14 


14.5 


24 


7 


29.17 


68 


6.4 


60 


16 


26.67 


15 


3-1 


17 








69 


6.8 


75 


22 


29-33 


18 


55 


88 


3 


3-41 


71 


3-9 


50 


19 


38.00 


19 


13.9 


80 


6 


7-50 


72 


1.6 


79 


28 


35-44 


20 


18.0 


76 


5 


6.58 


73 


•9 


38 


10 


26.32 


21 


33.8 


100 


2 


2.00 


75 


3-3 


80 


25 


31-25 


22 


36.2 


98 


4 


4.08 


76 


1-3 


71 


39 


54-93 


23 


9.4 


93 


II 


11.83 


77 


3-5 


79 


46 


58.23 


25 


7.1 


III 


15 


13-51 


78 


1-5 


74 


42 


56.76 


27 


29.6 


95 


10 


10.53 


79 


5-0 


71 


39 


5493 


29 


30.2 


49 


5 


10.20 


80 


5-4 


74 


20 


27.03 


31 


17.0 


48 


8 


16.67 


82 


4-7 


81 


45 


55-56 


32 


13.3 


98 


3 


3.06 


83 


4.2 


77 


29 


37-66 


33 


25.0 


55 


6 


10.91 


84 


4.1 


75 


39 


52.00 


35 


22.5 


81 


8 


9.88 


85 


4.3 


75 


28 


37-33 


36 


37-9 


82 


4 


4.88 












Totals . . . 


647.1 


2,099 


157 


223.53 




90.8 


1,862 


795 


1,170.07 


Average. . 


22.3 






7.48 




3-2 






42.70 



Medicago falcata. 



In regard to the quantity of seed produced an outstanding difference 
between sativa and falcata is noted, as is nearly or quite always the 



264 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



case, the production per plant of the former being in this instance 
about 7 times that of the latter. The variation constants of seed pro- 
duction are tabulated below. 

Mean, Standard devia- Variability, 

grams. tion, grams. percent. 

M. sativa 22.31 + 1.28 10.2541.91 45.95 +4-85 

M, falcata 3-24+ .24 1.90 + .17 58.50 + 6.84 

The seed production of the different plants of M. falcata is more 
variable than that of common alfalfa. If the greater variability is 
of significance it might be accounted for by the fact of pod dehis- 
cence, which factor might act unequally among the various plants. 

It is well to compare the quantities of seed produced with those 
obtained by Oakley and Garver (4) as an average for four years, in 
South Dakota. With them M. sativa yielded 2.19 grams per plant 
and M. falcata 0.35 gram. While the absolute quantities in the pres- 
ent experiment are much in excess over those quoted, the relative 
quantities are about the same. 

Of the 2,099 plants coming into bloom certainly having M. sativa 
for a pistillate parent, 157 indicated certain falcata flower color 
characters and were of hybrid origin. The percentage of hybrid 
plants is thus 7.48. Of the 1,862 blooming plants with M. falcata for 
a pistillate parent, 795 showed sativa flower characters and so were 
of hybrid origin, the percentage of hybridity thus being 42.70. 

Using the percentage hybridity means as a series of variates the 
constants of variation were found to be as follows : 

Mean, Standard devia- Variability, 

percent. tion, grams. percent. 

M. sativa 7.71 + .74 5.89 + .52 76.39 + 9.96 

M, falcata 41-79 +I-53 12.04 +1.09 28.81+2.80 

The unweighted mean is larger in one case and smaller in the 
other, than the corresponding weighted means. What is more to the 
point is the much greater variability in M. sativa than in M. falcata. 
It is not clear why this disparity should exist. 

The foregoing means indicate that the falcata plants of the parent 
plat were cross-fertilized to a much greater extent than were the 
corresponding sativa plants. Westgate (7) grew M. falcata along- 
side ordinary alfalfa. The resulting offspring plants, evidently com- 
ing from the M. falcata seed, were said to be hybrids, the implica- 
tion being that the hybridity was 100 percent. " In other exper- 
iments, the progeny of ordinary alfalfa grown associated with M, 
falcata has not shown any indication of M. falcata parentages." In 



WALDROX : CROSS-FERTILIZATION IN ALFALFA. 



265 



this case the falcafa plants were comparatively few in number. In 
my experiment all the 191 7 sativa parent plants produced some 
hybrid offspring except two and in both these instances but few plants 
were produced. 

The marked disparity of hybridity percentages in the reciprocal 
cross-fertilization secured by me indicates a rather strongly unbal- 
anced vicinism. This disparity was due in part to the difference in 
number of flowers between M. sativa and M. falcata and also to the 
comparative scarcity of pollen in M. falcata. It is evident that the 
results do not give a true criterion of the amount of cross-fertiliza- 
tion occurring between two alfalfa groups more properly balanced 
from a vicinal standpoint than the ones under trial. If the falcata 
plants had had more blossoms and a greater abundance of pollen, it 
seems likely that the percentage of hybridity would be located more 
centrally between the two extremes of 7 and 43 percent. 

It is evident, as previously indicated, that this experiment furnishes 
no measure of the amount of cross-fertilization undergone by any 
particular plant against all the remaining ones. Other experiments 
would have to be carried out to furnish data on this point. 

CORRELATION BETWEEN SEED PRODUCTION AND HYBRIDITY. 

Correlation coefficients were worked out between seed production 
and percentage of hybridity. The correlation was negative in both 
cases. For the M. sativa group it amounted to — .14 ± .12 and for 
the M. falcata group, — .20 ±.12. These coefficients are scarcely 
significant taken each by itself but their negative character in both 
cases strengthens the probability of the correlation as it appears. 

Assuming there is a real negative correlation, this would mean that 
the plants producing the smaller seed crop in 191 7 were cross-fertil- 
ized in greater measure. Or, an increase in the amount of cross- 
fertilization had an adverse effect upon seed production. This would 
seem to indicate a certain interspecific nonadaptability of pollen with 
the plants under experiment. The work of Piper et al., already 
cited, indicates that the pollen of M. falcata in fertilizing M. sativa 
is as efficient as that of M. sativa itself. 

Scarcely figuring as a part of this experiment is the character of 
the flower color of the M. sativa plants. Out of the 1,943 M. sativa 
plants which bloomed, there were 20 plants, or about i percent, 
which bore white flowers as the grandparent plant was said to do. A 
total of 12 plants produced the 20 white-flowered offspring. Some 
self-fertilized seed from the white-flowered plants was very light in 
color, the same as the seed from the grandparent. 



2 66 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

SUMMARY, 

In the foregoing experiment the two species of Medicago, sativa 
and falcata, were planted together in equal numbers to secure data 
on the amount of cross-fertilization taking place between the two 
species. 

Flowering records in the generation showed that the gametes 
of the M. sativa parent plants had united with gametes from the M. 
falcata plants to form mature sporophytes from M. sativa, to the 
extent of 7.48 percent. From M. falcata 4^.70 percent of hybrid 
plants were produced. The disparity was due probably in the main 
to the comparative scarcity of both flowers and pollen in M. falcata. 

A slight, but perhaps significant, negative correlation was found 
to exist between amount of seed produced in the parent plants and 
the extent of cross-fertilization. 

Literature Cited. 

1. Hansen, N. E. Cooperative tests of alfalfa from Siberia and European 

Russia. S. Dak. Agr. Expt. Sta. Bui. 141, p. 33-158. 1913. 

2. Hayes, H. K. Normal self-fertilization in corn. In Jour. Amer. Soc. 

Agron., 10: 123-126. 1918. 

3. Jones, D, F. The effect of inbreeding and crossbreeding upon development. 

Conn. Agr. Expt. Sta. Bui. 207, p. 59. 1918. 

4. Oakley, R. A., and Carver, Samuel. Medicago falcata, a yellow-flowered 

alfalfa. U. S. Dept. Agr. Bui. 428. 1919. 

5. Oliver, G. W. New methods of plant breeding. U. S. Dept. Agr., Bur. 

Plant Indus. Bui. 167. 1910. 

6. Piper, C. V., Evans, M. W., McKee, R., and Morse, W. J. Alfalfa seed 

production ; pollination studies. U. S. Dept. Agr. Bui. 75. 1914. 

7. Westgate, J. M. Variegated alfalfa. U. S. Dept. Agr., Bur. Plant Indus. 

Bui. 169. 1910. 



i 



AGRONOMIC AFFAIRS. 



267 



AGRONOMIC AFFAIRS. 

NOTES AND NEWS. 

Alfred Atkinson, agronomist of the Montana college and station, 
has been elected president of the Montana State College. He suc- 
ceeds James M. Hamilton, president during the past fifteen years, 
who has resigned to become professor of history and economics in the 
same institution. 

F. W. Brown, recently in charge of investigations of fertilizer re- 
sources of the United States in the Federal Bureau of Soils, is now 
executive secretary of the United States Potash Producers' Associa- 
tion, with headquarters in Washington, D. C. 

W. W. Burr is now assistant director as well as agronomist of the 
Nebraska station and during the recent absence of Dean Burnett on 
educational work in France was acting dean and director. 

E. O. Fippin, extension professor of soil technology in Cornell Uni- 
versity, has been granted a year's leave of absence, during which time 
he will act as director of the agricultural bureau of the National Lime 
Producers' Association. 

A. J. Galbraith, professor of chemistry of the Manitoba Agricul- 
tural College, died in December, 1918. At the time of his death he 
was engaged in a soil survey of Manitoba. 

L. F. Locke has succeeded L. N. Jensen as representative of the 
Federal office of dry-land agriculture at the Amarillo (Texas) Cereal 
Field Station. 

F. B. ]\Iumford, dean of the Missouri college of agriculture, is the 
agricultural representative of a commission of American universities 
to visit France with a view to cementing more closely educational and 
economic relations between the two countries. M. F. Miller is acting 
dean and director in his absence. 

J. J. Skinner of the Federal Bureau of Plant Industry has been 
awarded the Edward Longstreth medal of merit by. The Franklin 
Institute, for his paper, " Soil iVldehydes," which appeared in the 
Journal of The Franklin Institute from August to December, 1918. 
In presenting the medal, the Committee on Science and the Arts said : 
" These papers present the results of scientific study of a new class of 



268 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

deleterious soil constituents, clearly described and effectively illus- 
trated, the whole forming a valuable contribution to the science of 
agricultural chemistry, and one of marked practical importance." 

C. E. Trout, formerly of the Federal office of corn investigations, 
is now doing vocational agricultural work in the Jersey Township 
High School at Jerseyville, 111. 

Harry Umberger^ acting dean of extension in Kansas since Janu- 
ary i, on July i was made dean of extension. 

The Agricultural Index, begun in 1916, has now published a 3-year 
cumulation of all references to agricultural literature appearing in its 
pages during 1916, 1917, and 1918. This volume contains 1,056 pages, 
with 70,752 references. Not only are all Federal and State publica- 
tions on agriculture included, but also' 78 farm papers and technical 
journals, among the latter being the Journal of the American Soci- 
ety OF Agronomy. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. October, 1919. No. 7. 



TILLAGE: A REVIEW OF THE LITERATURE.^ 

M. C. Sewell. 

Introduction. 

The largest item of expense in producing cereal and annual forage 
crops is tillage. The most important tillage operations are plowing 
and cultivation. Any reduction in the depth of plowing, frequency 
of plowing, or number of cultivations necessary for economic yields 
materially reduces the cost of raising the crop. The prevailing opin- 
ions are so conflicting regarding plowing and cultivation that a review 
of the literature seems desirable to determine what conclusions can 
be drawn from the written evidence on the subject. 

Early History of Tillage. 

The history of tillage begins with the earliest written records of 
mankind. Sculpturings on the ancient Egyptian pyramids represent 
the use of the scarcle, a man-power tillage implement of the chopping 
spade type. Other sculpturings, 4,000 years old, depict a wooden 
plow drawn by animals. 

One writer ascribes the origin of tillage to the wild boar and the 
observation of ancient races that plants flourished in ground pre- 
viously rooted by wild boars (38).^ The first tilling of the soil was 
no doubt practised in order to enable the husbandman to get his seed 
or plant into the soil. The second step in soil stirring was occasioned 
by the necessity of combating intruding weeds. The agriculture of 

1 Contribution No. i6, Agronomy Department, Kansas Agricultural Experi- 
ment Station, Manhattan, Kans. Received for publication June 23, 1919. 

2 Figures in parentheses refer to " Literature cited," p. 287. 

269 



270 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Greece and Rome was founded on the theory that working of the soil 
was necessary because of the intractable soil and incursion of weeds. 
Virgil advocated good tillage. Since that period it has been believed 
that the soil is actually benefited by loosening and stirring ( i ) . 

The Early Philosophy of Tillage. 

Very little seems to be known of agricultural development during 
the middle ages. Until 1731, when Jethro TuU published his "New 
Horse-Houghing Husbandry" (59), there had been no discussions of 
soil tillage since the time of Virgil. Tull, an English landlord, while 
traveling in southern Europe observed the tillage between vineyard 
rows. On returning to England he adapted the system to the row 
culture of cereal crops. He believed that the earth was the only food 
of plants ; that the plant fed by taking in minute particks of earth, 
which were disengaged from the surface of the soil grains. Conse- 
quently, according to his theory, the more finely the soil was divided 
by tillage, the more numerous would be the particles that could be 
absorbed by the roots of plants. Insufficient tillage would leave the 
strong land with its natural pores too small and its artificial ones too 
large, while it would leave light land with its natural and artificial 
pores too large. As to weeds, he stated that they starve the plants 
by robbing them of their provision of food. Weeds never all come 
up in one year unless the land is often plowed. The best defence 
against these enemies, in his opinion, was a good summer fallow. 

Tull ascribed the benefits of manures to the dissolving and crum- 
bling effect they had on the soil. To this extent his theory was anti- 
Virgilian. According to the latter, land was pulverized by fire, and 
dung and harrows were used in place of the plow. The husbandry 
of England, especially along the southern coast, which was inhabited 
by Romans, was of this kind at the time of Tull's writing. 

With the beginning of the nineteenth century, development in the 
science of agricultural chemistry thru the work of Priestley (45), 
de Saussure (51), Davy (11), Boussingault (3), and Liebig (36), 
laid the foundation for the conception of the nutrition of plants as 
being based on the assimilation of certain chemical elements from the 
soil minerals, organic matter, water, and air. From this period the 
idea developed that tillage, by increasing the aeration of soil, increased 
oxidation of chemical compounds in the soil, rendering them more 
soluble in the soil solution. 

Gaylord (18), of Onondaga, N. Y., writing in 1 841, states that the 
end to be gained by tillage is the more effectual pulverization of the 



SFAVELL : TILLAGE LITERATURE. 



271 



soil and mixing it together so as to insure the united action of the 
whole in the production of the crop. Tillage, he claims, enables us 
to change the character of the soil in relation to moisture, temper- 
ature, and fertility. 

At a meeting of the New York Agricultural Society at Albany in 
1849, Lee (35), an editor from Augusta, Ga., presented the view that 
exhaustion of the soil is promoted by excessive plowing and hoeing. 
He believed that two-thirds of the tillage in the United States, espe- 
cially in the southern States, impaired the natural fertility of the soil. 
He attributed this to the greater oxidation of organic matter on the 
tilled land and to the leaching of the soil of its soluble mineral 
elements. 

The importance of deep tillage and subsoiling was brought to the 
attention of the Maine Department of Agriculture by Goodale (20) 
in i860. It was his opinion that these practices allowed roots to pene- 
trate deeply in search of food and moisture. The idea that the soil 
contains the necessary supplies of mineral matter and that tillage 
operations are capable of rendering these supplies available was dis- 
cussed by Goodale (21) in 1861 before the meetings of the Maine 
Department of Agriculture. 

Tanner (57) of Ohio, writing in 1861 of the mechanical conditions 
of the soil favorable for the growth of seed, states that the cultivator 
of the soil will find in the preparation of the land for the reception of 
seed his most laborious duty and that which demands his greatest 
judgment and skill. With heavy soil he found an early preparation 
advisable so that it can be thrown together in a dry state after which 
it remains untouched until seed time. 

The cultivation of field crops and preparation of soils was dis- 
cussed by Turner (60) in 1866 with reference to why plowing or cul- 
tivation of the soil is beneficial. He pointed out before the Maine 
Department of Agriculture that the old theory that tillage increases 
crop production by mixing ingredients already in the soil and pre- 
senting them more readily to roots is false. Since nine-tenths of 
plant substance comes from the atmosphere and since the roots of 
wheat extend 5 feet in depth and corn roots 10 feet, scratching the 
surface with plows and cultivators could be of small benefit. Accord- 
ing to his view, the real end in plowing is to put the soil in such con- 
dition that the plant may most readily absorb energy from the sun, 
and the moisture and other food elements from the air and soil. 

The view was presented by Sweet (55) of Maine in 1871 that an 
important result of tillage is the control of weeds. He quotes several 



2/2 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

experiments conducted in England in which weeds reduced the crop 
to a large extent. 

According to Johnson (26), in an address before the Connecticut 
Board of Agriculture in 1877, the tendencies in most soils is towards 
mechanical compacting and chemical petrifaction. One of the im- 
portant offices of tillage, he claimed, is to counteract these tendencies. 
He pointed out the effect of tillage in modifying the storage of water 
in the soil by changing the arrangement of the soil particles. He also 
recognized the necessity of different treatments for different soils. 

That root pruning explains in part the beneficial results of tillage 
was the belief of Sturtevant (54) in 1877, as expressed to the Con- 
necticut Board of Agriculture. Experiments in which corn plants 
grown in water cultures and in pot cultures were pruned, showed that 
pruning of the roots by checking their growth stimulated seed pro- 
duction. Cultivation, however, was found injurious if carried beyond 
the flowering stage of the plant. 

Davenport (10), in discussing the preparation of the soil for cereal 
crops in Maine in 1881, stated that the primary object of tillage was 
to stir and pulverize the surface of the soil that has been hardened 
and packed by rains. He believed that the finer the soil the more 
surface there is to hold moisture and for the action of the roots and 
that a well-cultivated soil seldom suffers from drouth. When wheat 
followed oats Davenport advocated plowing as soon as possible after 
harvest, and keeping the surface clean and loose thereafter. 

Under Missouri conditions. Waters (63) pointed out in 1887 that 
sod prevents surface washing and that excessive tillage increases it. 
The latter condition, he believed, is brought about by rapid oxidation 
and decomposition of vegetable matter induced by the circulation of 
air in the soil as a result of the cultivation. 

An EngHsli writer, Walden (61), in 1891 advocated thoro tillage 
and gave as his opinion that a skillful farmer requires comparatively 
little extra soil stimulant in the form of dung to grow a successful, 
crop. His belief that " implements make the best manuring " is not 
very far from the truth. 

Up to this period, literature on tillage has given only conflicting 
views upon the subject. From this time, experimental results were 
published which give more definite information. 

Preparation of Seedbeds. 

Morrow and Gardner (42) of Illinois compared in 1892 the yields 
o*^ corn on seedbeds plowed at depths varying from 2 to 10 inches. 
Their results are given in Table i. 



sewell: tillage literature. 273 



Table i. — Yield of corn from seedbeds plowed to various depths. 



Treatment, 1888 to 1893. 


Yield in 
bushels 
per acre. 


^ Treatment, 1890. 


Yield in 
bushels 
per acre. 


Not plowed; disked shallow 

Plowed 2 inches deep 

Plowed 4 inches deep 

Plowed 6 inches deep 

Plowed 8 inches deep 


56.4 
59-9 
69.4 

69-3 
71. 1 


Plowed 2 inches deep 

Plowed 5 inches deep 

Plowed 10 inches deep 


54-0 
57-5 
56,0 



None of these plots had any cultivation after planting, except re- 
moving the weeds by scraping the surface with a sharp hoe. The 
soil was one easily worked. It was loose, porous to considerable 
depth, and had great capillary attraction. They concluded that deep 
stirring of the soil for a crop is unnecessary and that air, water, and 
the roots of corn readily find their way into the soil even if it has not 
been stirred. 

In experiments with corn at the Indiana experiment station, Latta 
(32) found practically no difference in yield from plots plowed 8 
inches deep as compared with 4- to 4.5-inch plowing. These results 
were averages of yields obtained from 1886 to 1891, excluding- the 
year 1887 when no yield was obtained. In another experiment con- 
ducted for two years, 1 891-1892, there was practically no difference 
in the yield from plowing 6, 8, 10, and 12 inches deep. Plowing 4 
to 4.5 inches gave slightly smaller yields. 

The Indiana station (33) gives the average results for four years 
of the plowing experiments begun by Latta in 1891. These data are 
presented in Table 2. 



Table 2. — Average yields of corn produced at the Indiana station on land 
plowed to. various depths in the four years from 1891 to 1894, inclusive. 



Depth of plowing, inches. 


4 


6 j 8 


ID 


12 


14 


16 


Yield in bushels per acre 


33-77 


34-19 


35-14 


34-49 


35.00 


34-84 


34-14 



According to these averages there was a slight increase in yield 
with depth of plowing up to 8 inches. 

Sanborn (50), in 1892, compared different depths of plowing for 
wheat at the Utah experiment station. A plot was also included 
which had not been plowed. This plot was raw sage brush land and 
the sage brush was cut off level with the surface without stirring the 
soil. The wheat was planted with a hoe and at the same depth as in 
the other plots. The results are incorporated in Table 3. 



2/4 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 3. — Average yields of wheat obtained in a depth-of -plowing experiment 

at the Utah station. 

Average yield per acre for three years. 
Depth of plowing. Grains in bushels. Straw in pounds. 

Not plowed 8.6 1,013 

Plowed 4 inches deep 14.1 1,101 

Plowed 6 inches deep 13.3 i,ii3 

Plowed 8 inches deep 14.7 i,ii7 

Plowed 10 inches deep 14.4 i,3i7 

The unplowed plot gave the lowest yield, but there was only a 
slight difference in the yield from the other treatments. Similar re- 
sults were secured in a later experiment (49). There was, however, 
an increase in yield of straw with the depth of plowing. 

Merrill (39) conducted experiments in which the effect of depth 
of plowing on the yield of dry-land wheat was compared for five 
years at four different branch experiment stations in Utah and at 
one of them for an additional two years. The yields as reported in 
1910 are given in Tables 4 and 5. 

Table 4. — Average yields of wheat obtained in depth-of -plowing experiments 
conducted on four experiment farms in Utah during the five years from 
1904 to igo8, inclusive. 



Treatment. 


Juab 
County 
farm.« 


Washington 
County 
farm. 


Tooele 
County 
farm. 


Sevier 
County 
farm. 


Plowed 8 inches deep 


23-3 


II.6 


14.7 


5-3 


Plowed 10 inches deep 


23-4 


12.0 


14.9 


5-8 


Plowed 15 inches deep 


16.9 


15.2 


14.8 


6.8 


Plowed aad subsoiled 18 to 20 inches deep . 


15-4 


15.2 


16.2 


6.4 



Average yield in bushels per acre. 



" Heavy clay soil. 



Table 5. — Annual and average yields of wheat obtained in tillage experiments 
on the Washington Co., Utah, experiment farm in igoy and IQ08. , 





Yield of wheat in bushels per acre. 


Treatment. 










1907. 


1908. 


Average. 


Disked, not plowed 


27.9 


13-9 


20.9 


Plowed 5 inches deep 


25.0 


13-3 


19. 1 


Plowed 12 inches deep, not subsoiled 


29-3 


26.0 


27.7 


Plowed 16 inches deep, not subsoiled 


33-7 


21.0 


27.4 



In Washington County the results favor deep plowing. In all 
others nearly as good yields were secured from 8-inch as from deeper 
plowing. 



SEWELL : TILLAGE LITERATURE. 



In experiments conducted by G. W. Waters (62) in 1893 at the 
^Missouri station, subsoiling did not give better yields of corn than 
plowing 7 inches deep. 

In experiments at the New York station as cited by Waters, 
6-inch plowing in one experiment gave better yields than plowing 12, 
18, or 24 inches deep and nearly as high yields as plowing 30 inches 
deep. In still another experiment, 4-, 6-, and 8-inch plowing gave 
about the same yields, which were somewhat better than were secured 
from disking alone or from 2- to 4-inch plowing. 

Kraus (31) decided in 1894 that the greatest influence exerted upon 
the production of plants is the spacing, the second the effect of 
manuring, and the third the depth of plowing. These conclusions 
were based upon experiments at Weihenstephan, Germany, in which 
plants were seeded in wide and in narrow rows, with manured and 
unmanured treatments on both shallow and deep plowing. 

\\'ollny (67), in publications at Miinchen, Germany, in 1895, com- 
pared six treatments of the soil in field plots 4 meters square. The 
experiment included two plots each of three tillage treatments — un- 
worked, plowed 18 cm. deep, and plowed 36 cm. deep, one plot of 
each being fertilized and one unfertilized. The fertilizer used was 
guano applied at the rate of 200 gm. per plot (500 kg. per hectare). 
The soil was a calcareous loam containing 4.5 percent humus and 2 
percent calcium. During the four years previous to the experiment 
the field had grown potatoes and had been well fertilized. The ex- 
periment was conducted for three years, the crops grown being spring 
rye, maize, rape, flax, peas, sugar beets, potatoes, and horse beans. 
Wollny concluded that loosening of the soil increased its productive- 
ness and this increase in a majority of the cases was considerable. 
The increase was relatively small for rye, peas, horse beans, and flax ; 
and was relatively large for maize, rape, sugar beets, carrots, and 
potatoes. The fertilizer was most effective on the deep-plowed plots. 
According to Czerhati (9), cited by Wollny, the increase in yield 
from deep plowing for oats and barley was less than for maize. 
Kiihn was cited as having conducted experiments in which it was 
found that plowing a sandy soil which contained but little humus to 
a depth of 45 cm. produced almost as much barley as a soil plowed 
only 10 cm. deep. 

Later experiments by Wollny included an unworked treatment 
with the deep and shallow working of the soil. The results obtained 
did not occasion any change in the conclusions drawn from the pre- 
vious work. 



2/6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Tancre (56), a German investigator, advocated plowing imme- 
diately after harvest. Regarding the weathering of soils, he con- 
sidered the winter as the time of crumbling; the spring as the time 
of solubility ; and the summer as the time of fermenting of manure. 

In experiments at the Kansas station (19), in 1895-6, surface plow- 
ing for corn produced 34.0 bushels and subsoiling 33.4 bushels per 
acre. 

Shepperd and Jeffrey of the North Dakota Agricultural Experi- 
ment Station (53) reported, in 1897, the average yields of wheat for 
two years obtained by different methods of tillage. Plowing with a 
disk gang plow yielded 50 pounds less per acre than plowing with a 
moldboard. Subsoiling gave an increase of 39 pounds per acre but 
at a much greater cost. Deep plowing (8 inches deep) produced 43 
pounds per acre more than shallow plowing. 

Lyon (37) investigated the effect on the corn crop of deep plow- 
ing and subsoiling in Nebraska. Of 59 replies from questionnaires 
sent to farmers in Nebraska operating on clay subsoil, 80 percent 
favored subsoiling. Of those having a loam subsoil, 23 percent 
favored subsoiling. Reports from western Nebraska, where the soil 
and subsoil are porous, showed that subsoiling reduced the yields. 
In 1896 and 1897 shallow plowing (4 in. deep) both in the spring and 
fall gave better yields than deep plowing (8 in. deep), but disking 
gave lower yields than shallow plowing. 

Williams (65) obtained larger yields of corn in experiments con- 
ducted at the Ohio experiment station from 1891 to 1902 by culti- 
vating shallow than by cultivating deep. The average yields of 
grain were 56.4 bushels for deep cultivation and 60.4 bushels for 
shallow cultivation. 

Farrar and Sutton (16) reported in 1906 of different depths of 
plowing with disk and with moldboard plows on the yield of wheat, 
with fertilizer and without fertilizer in New South Wales. The 
average yields obtained are presented in Table 6. The moldboard 



Table 6. — Average yields of wheat in bushels per acre with different depths of 





plowing 


in New South 


Wales. 




Depth of plowing, 
inches. 


With fertilizer. 


Without fertilizer. 


Disk plow. 


Moldboard plow. 


Disk plow. 


Moldboard plow. 


4 
6 
8 


9-7 
8.6 
10.2 


14-5 
16.3 
16.5 


9-7 
8.5 
10.7 


13-3 
15-4 
14.8 



SEWELL : TILLAGE LITERATURE. 



277 



plow gave the highest yields in all cases. Eight-inch plowing gave 
higher yields than shallower plowing in most cases but the difference 
was small, probably not enough to pay the extra cost. 

Reitmair (46) in 1905 compared deep plowing (27 cm. or 10.6 in. 
deep) with shallow plowing (15 cm. or 5.9 in. deep) for several dif- 
ferent crops. In all cases the deep plowing produced larger yields, 
the dift'erence for oats being 27.8 bushels ; beans for hay, 0.22 ton ; 
and potatoes 6.3 bushels per acre in one instance and 32.5 bushels on 
a duplicate plot. Reitmair points out that there was not any essen- 
tial dift'erence in the nitrate supply of the deep-plowed field com- 
pared with the other and he could not explain the wide variation in 
the yields of the duplicate plots of potatoes. 

Kaserer (27) at Vienna, Austria, in 1906 compared plowing with 
the treatment of loosening the soil without plowing, on a sandy loam 
soil. Three plots were worked 20 cm. (7.8 in. deep) for beets with 
an extirpator, while two plots were plowed 20 cm. deep and left 
rough over winter. The two methods of preparation were also com- 
pared for wheat, barley, and corn. There was no material difference 
in the nitrogen content of the plots and no material difference in yield 
except for corn. For this crop, the results were much in favor of 
deep plowing. 

As an average of 40 trials during a period of three years at the ex- 
periment station at Davis, Cal., Shaw (52) found an average dif- 
ference of about 8 bushels of wheat and 6 bushels of barley in favor 
of deep plowing as compared with shallow plowing. The effect ap- 
peared to extend to the following crop, an average difference of 8 
bushels in the following crop of barley being observed. 

Baring (2) states that in tillage experiments in New South Wales, 
subpacking does not appear to increase the yield. Subsoiling and 
deep plowing failed to give increased yields, subsoiling apparently re- 
sulting in lower yields. The disk plow gave slightly better returns 
than the moldboard plow. 

Noll (44) reported in 191 3 on the results of three years' tests of 
deep (12-inch) plowing and ordinary (7.5 inch) plowing at the Penn- 
sylvania station. The yields of corn, oats, barley, wheat, alfalfa, 
clover, and timothy were compared. These crops were grown in 
rotation. The average yields, including more recent data as yet un- 
published, but kindly furnished the writer, fail to show any advan- 
tage for the deeper plowing. The average yields for 1910-1913 are 
presented in Table 7. 



278 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 7. — Average yields of grain in pounds per acre of various crops under 
various tillage methods at the Pennsylvania Agricultural Experiment 
Station during the four years from igio to 1913. 



Crop. 


Number of 


Yields in pounds per acre. 


years grown. 


7.5 inch plowing. 


12-inch plowing. 


Corn 


3 


4,128 


3.957 




I 


835 


792 


Oats 


2 


1.059 


1,086 


Wheat 


2 


1,240 


1,281 


Alfalfa 


3 


2,716 


2.774 


Clover and timothy 


2 


4,537 


4.483 



The draft per square foot of cross section of the furrow was de- 
termined and was found to average 1,113 pounds for the 12-inch 
plowing and 724 pounds for the 7.5-inch plowing. 

Wright (70), in 1914, reports five years' results with plowing ex- 
periments at the Oklahoma station in which 7-inch plowing gave the 
highest yield. There was no difference between the yields from 7-, 
8-, and 9-inch plowing. Subsoiling was unprofitable. The soil was 
an upland silt loam with an impervious subsoil. 

Williams and Welton (66), reporting in 1915, compared the aver- 
age yields for deep plowing, ordinary plowing, and subsoiling for 
corn, oats, wheat, and clover for a period of five years. The yields 
are presented in Table 8. 



Table 8. — Average yields of various crops under various tillage treatments at 
the Ohio Agricultural Experiment Station in a 5-year test. 



Crop. 


Treatment. 


Plowed 7.5 inches. 


Plowed 15 inches. 


Subsoiled. 


Corn (bu.) 


60.69 


61.12 


63.01 


Oats (bu.) 


45-49 


43-80 


45-11 


Wheat (bu.)« 


33-14 


33-37 


34-18 


Clover' (tons) 


2.43 


2-35 


2.34 



Average for four years only. 



The results show that there is not a consistent difference in favor 
of deep plowing or of subsoiling. 

Cardon (6), in a report on dry-land tillage experiments at Nephi, 
Utah, states that there was not any material difference in yields ob- 
tained from plots plowed at depths varying from 5 to 18 inches. 
There were eight plots employed, four being cropped each year and 
four fallowed. The depths of plowing for fallow were: (i) Sub- 
soiling 18 inches; (2) subsoiling 15 inches; (3) plowing 10 inches; 



SEWELL : 



TILLAGE LITERATURE. 



279 



and (4) plowing inches. Regarding soil moisture, it was found 
that there was no advantage in deep plowing or subsoiling, for the 
moisture content of the 5-inch plowing was as high as that of any of 
the other deeper treatments. 

Chilcott and Cole (8) concluded in 1918 that, as a general prac- 
tice, no increase of yields or amelioration of conditions can be ex- 
pected from subsoiling or other methods of deep tillage for the Great 
Plains as a whole. These conclusions are based on results of exten- 
sive experiments covering a wide range of crops, soils, and condi- 
tions, in ten different States in the Great Plains. The authors very 
aptly sum up the function of plowing in the following statements : 

It is mistaking or failing to recognize the purpose of plowing that leads to 
the belief that its efficiency increases with its depth even though that depth be 
extended below all practical limits of cost and effort. Plowing does not in- 
crease the water holding capacity of the soil, nor the area in which roots may 
develop or from which the plants may obtain food. Plowing removes from 
the surface either green or dry material that may encumber it, provides a sur- 
face in which planting implements may cover the seed, and removes or delays 
the competition of weeds or plants other than those intended to grow, and in 
some cases by loosening and roughening the immediate surface, checks the 
run-off of rain water. All of these objects are accomplished as well by plow- 
ing to ordinary depths as by subsoiling, dynamiting, or deep tilling by any other 
method. There is little basis, therefore, for the expectation of increased yields 
from these practices, and the results of the experiments show that they have 
been generally ineffective. 

^liller (41), in a study of the root systems of corn and the sor- 
ghums, isolated roots of these plants to a depth of over 6 feet and 
found the root development more extensive below the surface foot 
area of soil than above. From this fact, we may judge that deep 
plowing does not effect the depth of root penetration. 

Table 9. — Effect of depth of ploiving on yield in a rotation of corn, oafs, and 
wheat at the Kansas Agricultural Experiment Station during the six 
years from 1913 to 1918, inclusive. 



Average yield in bushels of grain per acre. 



Treatment. 


Wheat. 


1 Corn. 


Oats.« 


Plowed July 15, 


12 inches for wheat 


24.6 


22.1 


34-7 


Plowed July 15, 


7 inches for wheat 


24.2 


24.0 


37-6 


Plowed July 15, 


3 inches for wheat 


24.9 


' 22.9 


38.2 



^ Average for five years, no grain yield in 1916. 



Unpublished data of the Kansas Agricultural Experiment Station 
from the wheat seedbed rotation project do not give any appreciable 



280 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

differences in yields in 3-, 7-, and 12-inch plowing. These conclusions 
are based on the averages of six years' results. In this rotation, the 
wheat stubble is plowed in the fall 6 to 7 inches deep for corn, the 
corn stubble is disked in the spring for oats, and the oat stubble is 
plowed various depths for wheat. Table 9 presents the yields from 
this project. 

The Kansas station also has eight years' results with wheat cropped 
continuously under different seedbed treatments. The average yields 
are presented in Table 10. 

Table 10. — Average yields obtained from various methods of seedbed prepara- 
tion on land cropped continuously to wheat at the Kansas Agricultural 
Experiment Station in the eight years from igii to 1918, inclusive. 



Average yield in 

Treatment. bushels per acre. 

Disked at seeding time 6.8 

Plowed Sept. 15, 3 inches deep 12.7 

Disked July 15, plowed Sept. 15, 7 inches deep 17.5 

Disked July 15, plowed Aug. 15, 7 inches deep 18.2 

Listed July 15, ridges worked down 17.5 

Listed July 15, ridges split Aug. 15 17.4 

Plowed July 15, 7 inches deep 20.8 

Plowed Aug. 15, 7 inches deep, worked immediately 19.5 

Plowed Aug. 15, 7 inches deep, not worked until Sept. 15 18.1 

Plowed Sept. 15, 7 inches deep 13.5 

Plowed July 15, 3 inches deep 16.4 



These results show a decided benefit in the deeper early plowing 
(7 inches) over the shallow early plowing (3 inches) when wheat is 
grown continuously on the same land. Except in dry summers, the 
stubble on the August and September plowed plots is weedy unless 
it has been disked after harvest time. Moisture and nitrate deter- 
minations conducted in connection with this tillage project have led 
to the conclusion that early plowing is beneficial because it prevents 
weed growth and thus conserves available soil moisture and plant 
food (4). 

The conclusion is drawn from the references discussed under this 
head that deep plowing (more than 7 inches deep) in general does 
not increase crop yields. The question left unsettled is the depth of 
plowing less than 7 inches that produces the best results and the nec- 
essary frequency of plowing that depth. 



sewell: tillage literature. 



281 



The Cultivation of Crops, 
effect on soil moisture, nitrification, and yield. 

Intertillage of crops has been practised because it has been consid- 
ered beneficial aside from the control of weed growth. The general 
belief has been that cultivation conserved moisture by maintaining a 
soil mulch and, by aerating the soil, developed available plant food, 
thus promoting bacterial and chemical changes. 

Sanborn (49) found in his tillage investigations in Utah in 1893- 
1894, that the difference in moisture between land plowed and un- 
plowed was 0.63 percent in favor of the plowed. 

Grandeau (22), in 1894, in discussing the advantages and effects 
of deep cultivation in French agriculture, stated that old tillage prac- 
tices result in a lighter, better aerated soil, and that the capillary 
capacity of the soil is increased. These results, he believed, increased 
the nitrifying power of the soil, maintained the humidity of the sur- 
face soil in a more favorable condition for vegetation, and made the 
nutritive elements available by placing the radicles of plants closely 
in contact with the soil particles. Deep working during the summer 
was found to double the amount of water contained in the soil as 
compared with soil not worked. 

Kraus (31), in 1894, found the results of deep and shallow work- 
ing of corn and beets in Germany to favor the deep working. 

Miller and Brinkley (40), in 1897, reported yields of corn at the 
Maryland experiment station under deep and shallow cultivation. 
The depths were 6 to 7 inches and 2 to 3 inches. There was a gain 
of 2.4 bushels in favor of deep cultivation. They state that this gain 
was not enough to pay for the extra cost. 

Wollny (69) published an article in 1897 on the influence of the 
mechanical working of the soil upon its productiveness. Previous 
experiments at Miinchen, Germany, had shown that loosening the 
soil made it accessible to air and more easily saturated, but the effect 
of a pulverized condition had not been investigated. The crops grown 
in this experiment were flax, red clover, lucerne, and grass mixture. 
Yields were obtained four different years. The first experiments 
conducted in pots were verified by field plots on a clay loam soil. 
The plants without exception attained higher production in the 
crumbly soil than in the pulverized. Consequently, Wollny decided 
that the crumb structure characterized the condition of the soil to be 
striven for in a rational system of agriculture. 

The effect of loosening the soil upon the nourishment contained in 



282 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



the soil was also investigated by WoUny (69). Crumbly and pul- 
verized soils, fertilized and unfertilized, were compared. For fer- 
tilizer a mixture of equal parts of superphosphate, calcium chloride, 
and Chili saltpeter was used. The data show that the action of the 
fertilizer on the crumbly soil is greater than on the pulverized. 

In discussing farm practices that maintain the soil in a normal con- 
dition of structure, WoUny stated that tillage should take place im- 
mediately after harvesting the crop, otherwise the loose condition of 
the soil is lost after the crop covering is cut and the soil exposed to 
atmospheric precipitation. 

In answer to the question of when and how often the soil should 
be worked, Wollny concluded as a result of one year's experimenta- 
tion that fields requiring cultivation in the spring should be plowed 
in the fall ; that altho under certain conditions repeated workings 
of the soil in the spring were profitable, in the spring and summer 
land should be worked only when in a medium degree of moisture 
btcause with a higher or less degree of moisture the crumbly condi- 
tion of the soil would not result. 

Wollny also conducted experiments to determine the effect of hoe- 
ing upon plant production and the relation between the effect of 
loosening and the destruction of weeds without cultivation. He con- 
cluded that hoeing exercises a favorable effect upon plant production 
when practised on land loosened in the fall, but that it often proved 
injurious in its effect when the soil was in good mechanical condition 
and a long dryness simultaneously prevailed. 

The comparison of the hoed and the not hoed but weeded treat- 
ments proved that the production of plants was increased thru the 
surface loosening, but that hoeing culture attains its greatest success 
primarily by the destruction of weeds. 

The action of fertilizers was found by Wollny to increase with the 
depth of the tilled stratum, fertilization with the deeper degrees of 
tillage producing the greatest yields. 

In a later publication, Wollny (68) determined the properties of 
coherence, adhesion, and friction of soils. The data presented by 
him emphasize the advantage of the crumbly condition of the soil. 

Deherian (13), working under French conditions, compared the 
amount of moisture collected from drainage under the condition of 
vegetation compared with fallow. The average yearly percolation 
for three years was 417 liters from the soil without cultivation and 
440 liters from the soil cultivated. He concluded that loosening the 
soil favors the penetration of moisture. 



SEWELL : TILLAGE LITERATURE. 



283 



In 1897 Shepperd and Jeffrey (53) reported for the North Dakota 
Agricultural Experiment Station the average yields of wheat for two 
years obtained by different methods of tillage. Seeding in cultivated 
drills 24 inches apart produced 10.2 bushels less per acre than wheat 
sown in the ordinary way without cultivation. On fall plowed and 
spring plowed ground, there existed a slight difference in favor of 
shallow plowing as compared with deep. 

Deherain (14, 15), in 1900, inspired by the old proverb "two 
ploughings are equal of an irrigation," attempted to show exper- 
imentally why this may be true. His experiments were directed 
mainly to determining the eft'ect of a soil mulch in retarding the loss 
of water by evaporation. Moist soil was placed in vessels which 
w^ere weighed at intervals to determine the loss. A soil mulch was 
maintained by covering the surface with dry soil or by cultivation. 
The dift'erences in the loss of moisture were insignificant in most cases 
and Deherain concluded that a soil mulch has little effect in retarding 
evaporation. In later experiments he fovmd that plants growing in 
the soil were the principal means by which water was removed. He 
advanced the idea that plowing and weeding wxre of equal value. 

Williams (65) obtained larger yields of corn in experiments con- 
ducted at the Ohio Agricultural Experiment Station from 1891 to 
1902 by cultivating shallow than by cultivating deep. The average 
yields of grain were 56.4 bushels for deep cultivation and 60.4 bushels 
for shallow cultivation. 

Welborn (64), in 1908, compared the yield of corn and cotton 
grown with deep (6-inch) and with shallow cultivation at the Texas 
Agricultural Experiment Station. He failed to find any advantage 
for deep cultivation. 

Knight of the Nevada station (30) compared in 1908 the effect of 
mulches of different depths on checking the loss of water by evapora- 
tion. Soil containers were used, and the dry earth mulch was applied 
to the wetted soil. The effect is shown in Table 11. 



Table ii. — Soil container experiments zvith mulches. 



Depth of mulch. 

Water surface . . . . 
No mulch 



Water loss in inches. 



Percentag^e of the total 
water loss. 



3-inch mulch 
6-inch mulch 
9-inch mulch 



4.68 
1.41 
.88 
.36 
■17 



78.0 
23.6 
14.6 
6.0 
2.9 



In this experiment where the mulch consisted of dry soil applied 
to the wetted soil, the soil mulching was effective and increased in 



284 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

efficiency with the depth. However, another experiment is reported 
by Knight in which the soil containers were irrigated and the soil 
mulch established by cultivation. Compared with a water surface 
loss of 8.49 inches, the soil surface cultivated 6 inches in depth lost 
1.09 inches of water and the uncultivated soil, 1.51 inches. In this 
instance, the difference in loss is not great. 

Gates and Cox (7), in 1912, tabulated the results of 125 exper- 
iments carried on for six years, 1906-1911, in 28 different States. 
They concluded that cultivation is not beneficial to the corn plant 
except in the removal of weeds. 

Hosier and Gustafson (43), in 191 5, showed as a result of eight 
years' work at the Illinois Agricultural Experiment Station that 
killing weeds without cultivation produced a gain of 17.1 percent or 
6.7 bushels per acre over ordinary cultivation (shallow three times). 

Thom and Holtz (58) found at the Washington Agricultural Ex- 
periment Station in 1914 that tillage materially affected the amount 
of precipitation absorbed by the soil. With a total precipitation of 
9.56 inches, land in stubble absorbed 5 inches ; disked stubble absorbed 
6.25 inches ; and stubble disked after harvest and fall plowed ab- 
sorbed 7.25 inches. 

Harris and Bracken (23), reporting in 191 7 on the results of soil 
moisture studies under irrigation similar to those reported for dry 
farming at the Utah station, show that cultivation was more effective 
in conserving moisture than pulling weeds ; the difference, however, 
was not great. The advisability of mulching with straw as compared 
with cultivation eight days after water is applied hinges on the ques- 
tion of labor. The difference in moisture content of the soil mulched 
with 2 inches of straw and soil cultivated 2 inches deep was i per- 
cent, and between cultivating 2 inches deep and no cultivation but 
with weeds pulled, was i percent. 

Hutcheson, Hodgson, and Wolfe (25) as a result of corn cultiva- 
tion experiments at Virginia Agricultural Experiment Station, 191 3- 
1916, concluded that cultivation of corn is advantageous. Table 12 
presents their average results. 



Table 12. — Average yields of grain and fodder obtained from different methods 
of cultivating corn at the Virginia station in the five years from 1913 
to 1916, inclusive. 



No cultivation, weeds 
growing. 


No cultivation, weeds 
cut with hoe. 


Three cultivations. 


Five cultivations. 


Grain, 
bu. 


Fodder, 
tons. 


Grain, 
bu. 


Fodder, 
tons. 


Grain, 
bu. 


Fodder, 
tons. 


Grain, 
bu. 


Fodder, 
tons. 


8.4 


0.7 


49.0 


1.4 


59.4 


1.6 


58.6 


1-5 



SEWELL : TILLAGE LITERATURE. 



285 



Call and Sewell (4), as a result of three years' studies with soil 
mulches, showed in 191 7 that for silt loam types of soil with Kansas 
conditions, the maintenance of a soil mulch had practically no effect 
in reducing evaporation. It was also found that nitrate development 
was as extensive without cultivation as with cultivation. Later results 
(5), 1918, showed that cultivation by preventing weed growth con- 
served the soil's supply of available plant food, and that too much 
emphasis had been placed on tillage as related to moisture conserva- 
tion and the development of plant food. 

At the Kansas station, data regarding the effect of tillage on corn 
yields are available for the five years from 1914 to 1918, inclusive. 
These results are presented in Table 13. 



Table 13. — Annual and average yields of corn variously cultivated at the 
Kansas Agricultural Experiment Station during the five years from 
1914 to 1918, inclusive. 









Yield per acre. 






Cultivation treatment. 












Aver- 




1914. 


1915a. 


1916*. 


1917c. 


i9i8<^. 


age, 














1914-17. 




Bu. 


Bu. 


Bu. 


Bu. 


Lbs. 


Bu. 


Ordinary 


13-0 


65.0 


43-9 


39-6 


8,457 


40.4 


Ordinary and i -horse cultivator to main- 














tain mulch 


13-4 


62.0 


43-3 


39-5 


8,000 


39-5 


Ordinary and i-horse cultivator every lo 
















II. 


58.8 


43-4 


39-6 


8,850 


38.2 


Not cultivated ; weeds hoed by hand 


9.2 


65.0 


45-2 


35-0 


7,580 


38.6 



" Average yield upland and bottom land, fall plov^^ed, 
^ Average yield, fall plowed, spring plowed, and disked. 
^ Average yield, fall plowed and unplowed land. 
^ Silage yields in pounds. No grain yield in 1918. 



As an average of the four years, 1914-17, the uncultivated plots 
where the weeds were removed produced practically as great yields 
as the cultivated plots. Apparently there was not any advantage 
from the point of yield in cultivating corn, except for the purpose of 
killing weeds. The small differences in yield are considered within 
the experimental error. 

These various citations on intertillage and cultivation, with the ex- 
ception of the writings of Grandeau (22) and Kraus (31) and the 
results at the Virginia Agricultural Experiment Station (25), show 
but little if any differences in the effect of cultivated and uncultivated 
treatments in regard to yields, conservation of moisture, and nitri- 
fication. 



286 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

SOIL \ERATION AND NITRIFICATION. 

Concerning the viewp oint that it is necessary to promote oxidation 
in various chemical changes and furnish sufficient oxygen for bac- 
terial activity, while it is recognized that oxygen is essential for 
chemical and bacterial changes in the soil, soils with natural drainage 
and in climates of medium or well distributed precipitation may be 
of such a type texturaFy that they have sufficient aeration without 
cultivation practised for that particular purpose. Citations of ex- 
perimental work proving this supposition have already been reviewed 
(5), but may with advantage be repeated in this article on tillage. 

In 1902, King and Whitson (29) presented investigations at Wis- 
consin on the effect of increasing aeration on nitrification. They 
bored holes in the soil and determined nitric nitrogen in the sur- 
rounding area. The data obtained did not indicate that nitrification 
was increased by this manner of aerating the soil. 

In 1906, Day (12) attempted to determine experimentally the 
effect of artificial aeration of soils at the Ontario Agricultural Col- 
lege for wheat, barley, oats, and peas. The plants were grown in 
crocks in duplicate. Air was forced through the soil of one set once 
a day. There was not a benefit from the aeration of any of the 
crops except peas, which were very much benefited the first year. 
The effect of aeration on the peas was not as great the second year. 

Russell and Appleyard (48), in 191 5, reported results in England 
showing but little variation in the composition of atmospheric and 
soil air. 

Leather (34) found that in the soils of India the diffusion of gases 
through soils at a depth of 12 to 15 inches is so efficient as to war- 
rant the conclusion that cultivation of the surface soil is unnecessary 
for purposes of aeration. His investigations showed that even dur- 
ing the wettest weather, the volume of gas falls only to 15 to 20 per- 
cent of the soil volume or about half that which is present during 
long periods of hot, dry weather. 

Gainey and Metzler (17) of the Kansas Agricultural Experiment 
Station, in 1916, from laboratory studies of the rate of nitrification 
in a compacted and an uncompacted soil, found greater nitrification 
on the compacted soil up to the point where the moisture content 
reached two-thirds saturation. 

We may judge from these various reports on aeration of the soil 
that many soils naturally have sufficient aeration for optimum bac- 
terial and chemical activity without cultivation. 



. sewell: tillage literature. 



287 



General Summary. 

In general, we may conclude that the prevt^iling theories advocating 
deep plowing and frequent cultivation are not founded upon exper- 
imental evidence. 

The review of tillage literature leads to the following conclusions : 

(1) Plowing deeper than 7 inches has not generally resulted in an 
increase of crop yields. ^ 

(2) Shallow^ plowing may produce as great yields as deeper plow- 
ing, but the depth less than 7 inches which is best for economic pro- 
duction has not been determined. 

(3) The question of frequency of plowing has not been answered, 
but it seems possible by proper rotation of crops to lessen the number 
of plowings. 

(4) Cultivation may be necessary only to kill weeds and keep the 
soil in a receptive condition to absorb rainfall. Thus it is practical, 
except on very heavy soils, to reduce the amount of cultivation where 
the guiding policy is that of thoro cultivation in order to maintain a 
soil mulch. 

Literature Cited. 

1. Bailey, L. H. Treatment of soil by means of tillage. In Cyclopedia of 

American Agriculture, i : Z7^-Z7^- The Macmillan Co., New York, 1907. 

2. Baring, E. Plowing experiments. In Agr. Gaz. N. S. Wales, 23 : 967-968. 

1912. 

3. BoussiNGAULT, Jeax B. J. D., and Dumas, J. B. A. Agronomic, chimie 

agricole et physiologic. 1884. 

4. Call, L. E., and Sewell, M. C. The soil mulch. In Jour. Amer. Soc. 

Agron., V. 9, no. 2, p. 49-61. 1917. 

5. . The relation of weed growth to nitric nitrogen accumulation in the 

soil. In Jour. Amer. Soc. Agron., v. 10, no. i, p. 35-44. 1918. 

6. Cardon, p. V. Tillage and rotation experiments at Nephi, Utah. U. S. 

Dept. Agr. Bui. 157. 1915. 

7. Gates, J. S., and Cox, H. R. The weed factor in the cultivation of corn. 

U. S. Dept. Agr., Bur. Plant Ind. Bui. 257. 1912. 

8. Chilcott, E. C, and Cole, John S. Subsoiling, deep tilling, and soil dyna- 

miting in the Great Plains. In Jour. Agr. Research, v. 14, no. 11, p. 481- 
521. 1918. 

9. Czerhati, a. Die Eigenbisse der Tief Kulture in Ungarn. Wien, 1892. 

10. Davenport, Eugene. Preparation of soil for cereal crops. In Ann. Rpt. 

Maine Bd. Agr. for 1881, p. 222-226. 1881. 

11. Davy, Humphry. The decomposition of the fixed alkalies and alkaline 

earths. In Alembic Club Reprints, no. 6, p. 36; Bakerian Lecture 1806, 
p. 8. 1807-08. 

12. Day, W. H. Plowing experiments. In 326. Ann. Rpt. Ontario Agr. Col. 

and Expt. Farm, p. 36. 1906. 

13. Deherian, p. p. The cultivation of the soil. In Ann. Agron., 23: 216- 

229. 1897. 



288 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

14. . The cultivation of the soil. In Rev. Gen. Agron., 9: 405-412. 1900. 

15. . Ploughing and weeding. In Ann. Agron., 26: 257-261. 1900. 

16. Farrar, W., and Sutton, G. L. Plowing with moldboard and disk plows. 

In Agr. Gaz. N. S. Wales, v. 17, no. 4, p. 320-326. 1906. 

17. Gainey, p. L., and Metzler, L. F. Some factors affecting nitrate nitrogen 

accumulation in the soil. In Jour. Agr. Research, v. 11, no. 2, p. 43-64. 
1917. 

18. Gaylord, Willis. On tillage. In Trans. N. Y. State Agr. Soc, i : 211- 

221. 1841. 

19. Georgeson, C. C., Burtis, F. C., and Otis, D. H. Corn tillage experiment. 

Kans. Agr. Expt. Sta. Bui. 64. 1897. 

20. GooDALE, Geo. L. Under drainage and deep tillage. In Maine Abs. of 

Returns from the Agricultural Societies, p. 122-138. i860. 

21. GooDALE, Stephen Lincoln. Cultivation a fertilizing agency as really as is 

manure. In 6th Ann. Rpt. Maine Dept. Agr., p. 72-89. 1861. 

22. Grandeau, L. Advantages et effets de labour profunds. In Jour. Agr. 

Prat., ann. 58, t. 2, no. 4, p. 487-490. 1894. 

23. Harris, F, S., and Bracken, A. F. Soil moisture studies under irrigation. 

Utah Agr. Expt. Sta. Bui. 159. 1917. 

24. Hilton, H. R. Some problems in tillage. In Kans. State Bd. Agr. Bien. 

Rpt. 1895-1896, p. 11-20. 1897. 

25. Hutcheson, T. B., Hodgson, E. R., and Wolfe, T. K. Corn culture. Va. 

Agr. Expt. Sta. Bui. 214. 1917. 

26. Johnson, S. W. On reasons for tillage. In nth Ann. Rpt. Conn. Bd. 

Agr., p. 133-151. 1878. 

27. Kaserer, Hermann. Ein Versuch der Bodenbearbeitung ohne Pflug. In 

Ztschr. Landw. Versuchsw. Oesterr., Jahrg. 14, Heft 9, p. 1123-1131. 
1911. 

28. King, F. H. Tillage : Its philosophy and practise. In Bailey's Cyclopedia 

of American Agriculture, i : 378^387. New York, 1907. 

29. , and Whitson, A. R. Development and distribution of nitrates in 

cultivated soils. Wis. Agr. Expt'. Sta. Bui. 93. 1902. 

30. Knight, C. S. Irrigation of wheat in Nevada. Nev. Agr. Expt. Sta. Bui. 92. 

31. Kraus, C. Zur Kenntniss der Wirkungen der Tiefkultur. In Fiihhngs 

Landw. Ztg., Jahrg. 43, Heft 9, p. 291-295. 1894. 

32. Latta, W. C. Experiments with corn. Ind. Agr. Expt. Sta. Bui. 23, 1889. 

33. . Plowing deep and shallow for corn. In 8th Ann. Rpt. Ind. Agr. 

Expt. Sta., p. 37. 1895. 

34. Leather, J. W. Soil gases. In Mem. Dept. Agr. India, chem, ser., v. 4, 

no. 3, p. 65^-106. 1915. 

35. Lee, Daniel. The philosophy of tillage. In Trans. N. Y. Agr. Soc, 8: 

342-358. 1849. 

36. Liebig, Justus. Chemistry in its applications to agriculture and physiology. 

Edited by Lyon Playfair. London, 1840. 

37. Lyon, T. Lyttleton. Effect of certain methods of soil treatment upon the 

corn crop. Nebr. Agr. Expt. Sta. Bui. 54. 1898. 

38. McCoNNELL, Primrose. Tillage implements, old and new. In Trans. High- 

land and Agr. Soc. Scot., v. 6, 5th ser., p. 206-238. 1894. 
Methods of tillage, old and new. Trans. Highland and Agr. Soc. Scot., 
v. 17, 5th ser., p. I2i-iz^4. 1905. 



SEWELL : TILLAGE LITERATURE. 



289 



39. Merrill, Lewis A. A report of seven years' investigation of dry-farming 

methods. Utah Agr. Expt. Sta. Bui. 112. 1910. 

40. Miller, R. H., and Brinkley, E. H. Corn and potato experiments. Md. 

Agr. Expt. Sta. Bui. 46. 1897. 

41. Miller, Edwin C. Root systems of agricultural plants. In Jour. Amer. 

Soc. Agron., v. 8, no. 3, p. 129-154. 1916. 

42. Morrow, G. E., and Gardner, F. D. Field experiments with corn. 111. 

Agr. Expt. Sta. Bui. 20. 1892. 

43. Mosier, J. G., and Gustafson, A. F. Soil moisture and tillage for corn. 

111. Agr. Exp. Sta. Bui.. 181. 1915. 

44. XoLL, C. F. Deep versus ordinary plowing. In Rpt. Pa. State Col. for 

1912-1913, part II, p. 39-47- 1913. 

45. Priestley, Joseph. Experiments and observations on different kinds of air 

and other branches of natural philosophy connected with the subject. 3 
vols. Thomas Pierson, Birmingham, Eng. 1790. 

46. Reitmair, Otto. Abteilung fiir Pflanzenbau. In Ztschr. Landw. Versuchsw. 

Oesterr., Jahrg. 8, Heft 3, p. 192-206. 1905. 

47. Roberts, Isaac P. Science of tillage and productivity of land. In Ann. 

Rpt. N. Y. State Agr. Soc, 54: 513-519. 1894. 

48. Russell, E. J., and Appleyard, A. The atmosphere of the soil, its compo- 

sition, and the causes of variations. In Jour. Agr. Sci. (England), v. 7, 
pt. I (1915), p. 1-48. 1915- 

49. Sanborn, J. W. Methods of ploughing. In Ann. Rpt. Utah Agr. Expt. 

Sta., p. 91-107. 1892. 

50. . Methods of ploughing. In Ann. Rpt'. Utah Agr. Expt. Sta., p. 107- 

129. 1893. 

51. Saussure, Theod. de. Chemische Untersuchungen iiber die Vegetation. 

Uebersetzt von A. Wieler. Halfte i, 96 p., i pi. Leipzig, 1890. (Klas- 
siker der Exakten Wissenschaften, 15.) 

52. Shaw, G. W. How to increase the yield of wheat in California. Cal. Agr. 

Expt. Sta. Bui. .211. 1911. 

53. Shepperd, J. H., and Jeffrey, J. A. A study of methods of cultivation. 

X. Dak. Agr. Expt. Sta. Bui. 29. 1897. 

54. Sturtevant, E. Lewis. Intercultural tillage. In Rpt. Conn. Bd. Agr. for 

1877-8, p. 190-204. 1878. 

55. SwETT, Col. Clean culture. In i6th Ann. Rpt. Maine Bd. Agr., p. 332-341. 

1871. 

56. Tancre. Zur Bodenbearbeitung. In Fiihlings Landw. Ztg., Jahrg. 46, Heft 

4, p. 98-105. 1897. 

57. Tanner, Henry. The mechanical conditions of the soil favorable for the 

growth of seed. In i6th Ann. Rpt. Ohio Bd. Agr., p. 290-312. 1861. 

58. Thom, C. C, and Holtz, H. F. Dry farming in Washington. Wash. Agr. 

Expt. Sta. Pop. Bui. 69. 1914. 

59. TuLL, Jethro. Horse-hoeing husbandry. William Corbett, London, 1829. 

60. Turner, J. B. On the cultivation of field crops and preparation of soils. 

In Maine Dept. Agr. Abstract of Returns from the Agricultural Socie- 
ties, p. 70-^8. 1866. 

61. Walden, W. J. Tillage and manuring. Geo. Bell and Sons, York Street, 

Covent Garden, London. 1891. 

62. Waters, G. W. Tillage. In 26th Ann. Rpt. Mo. Bd. Agr., p. 199-207. 1893. 



290 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

63. Waters, H. J. Relation of tillage to soil conservation. In 20th Ann. Rpt. 

Mo. Bd. Agr., p. 189-198. 1888. 

64. Welborn, W. C. Corn and cotton experiments for 1908. Texas Agr. Expt. 

Sta. Bui. 120. 1909. 

65. Williams, C. G. The corn crop. Ohio Agr. Expt. Sta. Bui, 140. 1903. 

66. , and Welton, F. A. Corn experiment's. Ohio Agr. Expt. Sta. Bui. 

282. 191 5. 

67. WoLLNY, E. Untersuchungen liber den Einfluss der mechanischen Bear- 

beitung auf die Fruchtbarkeit des Bodens. In Forsch. Geb. Agr. Phys., 
Bd. 18, Heft 1/2, p. 63-75. 1895. 

68. . tjber die Bearbeitbarkeit der Boden. In Deut. Landw. Presse, Jahrg. 

25, No. 80, p. 856; No. 88, p. 932^33; No. 89, p. 941-942. 1898. 

69. . Untersuchungen iiber den Einfluss der mechanischen Bearbeitung 

auf die Fruchtbarkeit des Bodens. (Zweite Mittheilung.) In Forsch. 
Geb. Agr. Phys., Bd. 20, Heft 3, p. 231-290. 1898. 

70. Wright, A. H. Dry plowing and subsoiling. Okla. Agr. Expt'. Sta. Circ. 

26. 1914. 



STAKMAN, HAYES, AAMODT AND LEACH : FLAX WILT. 



291 



CONTROLLING FLAX WILT BY SEED SELECTION.^ 

E. C. Stakman, H. K. Hayes, Olaf S. Aamodt, and J. G. Leach. 

Introduction. 

Statistics of the United States Department of Agriculture- show 
that the principal area of flax production has in the last half century 
moved steadily westward from Kentucky and Ohio to the present 
area including Minnesota, North Dakota, South Dakota, and Mon- 
tana. These figures show also that the annual production of flaxseed 
in this country is steadily declining. The average yearly production 
for the years from 1900 to 1909 inclusive was 25,966,700 bushels. 
For the next seven years, from 1910 to 1916 inclusive, the average 
production was only 17,155,571 bushels. In Minnesota the average 
yearly production from 1902 to 1909 was 5,322,000 bushels, while 
from 1 910 to 191 7 the yearly average was only 3,051,125 bushels. 
The conditions were similar in Iowa, North Dakota and South 
Dakota. 

Since flax does not compete with weeds as well as some other crops 
do, new land is especially desirable for flax production. This would, 
in a measure, account for the above facts. It is very reasonable to 
suppose, however, that flax wilt is at least of equal or even of greater 
importance in causing this decrease in yield as well as the migratory 
movement of the crop. It is well known that when flax is grown for 
a number of successive years on the same soil, this soil becomes so 
heavily infected with the fungus causing flax wilt (Fusariuin lini 
Bolley) that a profitable crop cannot be grown. Soil in this condition 
is usually spoken of as being " flax-sick." It is easy to conceive the 
effect this would have on the total flax production, directly by reduc- 
ing the yield and indirectly by discouraging its culture. The gradual 
movement of the center of production to new lands is a natural 
sequence. 

THE ROLE OF SELECTION IN CONTROLLING WILT DISEASES. 

Bolley (i, 2Y first discovered the true nature of flax wilt and de- 
vised methods for its control. Crop rotation and seed treatment were 

1 Published, with the approval of the Director, as Paper 179 of the Journal 
series of the Minnesota Agricultural Experiment Station, University Farm, 
St. Paul, Minn. Received for publication August 17, 1919. 

2 U. S. Dept. Agr. Yearbooks. 

3 Reference is to " Literature cited," p. 298. 



292 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

found helpful, but the most promising control measure appeared to 
be the use of wilt-resistant seed. Bolley (3, p. 177) states that a few 
straggly plants survived the first year when varieties were grown on 
flax-sick soil. These were selected and the progeny were somewhat 
resistant the following year. After several years of selection, sorts 
were produced which yielded well on flax-sick soil. It is interesting 
to note that similar methods failed when applied to developing rust- 
resistant wheats. The difference in behavior of these two crops and 
the biological cause of development of resistant flax sorts by con- 
tinuous selection are unanswered questions. 

Methods similar to those mentioned above have been successfully 
applied by various workers to the control of wilt diseases of several 
crops. Orton (6, 7) succeeded in reducing losses from the wilt dis- 
ease of cotton caused by Fusarium tracheiphilum, by selecting seed 
from individual resistant cotton plants which survived in heavily in- 
fected fields. This work resulted in the production of several wilt- 
resistant varieties of commercial value. These are being grown with 
success in wilt-infested areas of the south. 

Jones and Gilman (5) employed the same methods in combating 
cabbage yellows, caused by Fusarium conglutinana. 

The fusarium wilt of tomato {Fusarium lycopersici) has been suc- 
cessfully overcome by Essary (4). The same general plan was fol- 
lowed, resulting in the development of sorts possessing a high degree 
of resistance as well as other desirable characters. 

Selection of wilt-resistant varieties, then, should offer a practical 
solution of the flax-wilt problem. The figures cited above show, 
however, that flax production is decreasing, and they strongly indicate 
that it will continue to decrease unless some effective method of con- 
trol is put into general practice. The problem now is to produce wilt- 
resistant varieties of flax of good yielding ability and to bring them 
into general cultivation. It is the belief of the writers that sufficient 
attention has not been given by pathologists and agronomists to the 
production and distribution of resistant varieties of flax. 

Little confirmatory evidence of Bolley's remarkable work in de- 
veloping wilt-resistant flax has ever been published. The writers are 
of the opinion that the problem is sufficiently important and the 
methods so well tried as to make the publication of supplementary 
data valuable. This paper summarizes the result of four years of 
selection of flax for wilt resistance. This work was done with the 
object of determining the efficiency of the method and to call atten- 
tion to a simple plan adapted to the use of plant breeders, agron- 
omists, and intelligent farmers. 



STAKMAN, HAYES, AAMODT AND LEACH : FLAX WILT. 293 



METHODS AND MATERIALS. 

Preliminary work was begun by the senior author in 191 1. In 1914 
several varieties and selections of flax, obtained from the Division of 
Agronomy and Farm Management of the Minnesota Agricultural 
Experiment Station, were sown on flax-sick soil. In order to insure 
a heavily infected disease plot the soil was sprayed at intervals with 
a water suspension of spores of Fusarium lini. Very good results 
were obtained in this way. All of the varieties planted proved to be 
very susceptible, from 50 to 100 percent of the plants being killed by 
wilt. Pure cultures of Fusarium lini were obtained from the diseased 
plants. 

Seed selected in bulk from the surviving plants were planted again 
in 191 5 on the same soil. Seed from the original nonselected vari- 
eties were planted as checks. It was not found necessary to spray 
the soil with the spore suspension after the first year, since the soil 
remained heavily infected and in fact became more heavily infected 
the second year. This was shown by the fact that practically 100 
percent of the check plants were killed by wilt in 191 5. Bulk and in- 
dividual plant selections were made in 191 5 and 1916. Bulk selec- 
tions only were made in 191 7. These selections were sown each year 
on the same soil, nonselected varieties being planted as checks. 

RESULTS OF SELECTION. 

Table i shows the results of the four years of selection. It will be 
noticed that in most cases a high degree of resistance was obtained by 
selection while from 75 to 100 percent of the nonselected plants 
proved to be susceptible each year. It will also be seen that the degree 
of resistance developed by selection was by no means always con- 
sistent. Selections from some varieties produced a high percentage 
of resistant plants after having been selected only once ; the degree 
of resistance of others apparently increased with each successive selec- 
tion. Some showed increased resistance after one selection, but in 
the following year seemed to lose all that had been gained. In a few 
cases there was no appreciable increase of resistance. It should be 
noted, however, that with the small am^ount of seed planted, especially 
in the case of individual selections, there is great chance for variation. 
For this reason, when drawing conclusions as to the mechanism in- 
volved in the production of wilt resistance, very little importance 
should be attached to these figures. More extensive work is neces- 
sary before the question of the mechanism involved can be answered 
The essential fact is that a high degree of resistance actually can be 
obtained. 



294 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



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STAKMAX, HAYES, AAMODT AND LEACH : FLAX WILT. 295 



i 


Type of 
selection. 




do. 
do. 
do. 

do. 
do. 
do. 
do. 
do. 

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do. 
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do. 

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do. 
do. 
do. 

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Russian, Dept. No. 9969 

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Minn. 

Accession 
No. 





296 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

In 1918 it was thought desirable to test more accurately and on a 
more extensive scale the real value of the resistant selections. Ac- 
cordingly all the poorer selections were discarded and all available 
seed of the most promising sorts were used to make an exftensive 
yield test. The test was made at two places, at the University Farm, 
St. Paul, Minn., and at Waseca, Minn. The selections were sown on 
flax-sick soil in 3-row plats, each plat being replicated two times. In 
computing the yields all three rows of each plat were considered. 
Ten-foot rows were planted at St. Paul and thirty-foot rows at 
Waseca. Table 2 shows the results of these tests. 



Table 2. — Yield in bushels per acre of selected and nonselected flax on ''flax- 
sick " soil in 19 iS. 





St. Paul. 


Waseca. 




























Selection No. 


It wi 
urit} 










be 
a 


, old 








4; 

be 


St. Paul 
and 






V 






V 


i- — <" 

I' 




u 






Waseca. 




Per. 
at in 






C/} 


> 
< 


, win 






CO 


> 
< 




Class I 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


Bu. 


25 


5 


6.34 


8.23 


12.00 


8.86 





16.86 


13.20 


11.60 


13-88 


11-37 


67 


5 


5-65 


4-45 


5-83 


5.16 





12. II 


9-83 


4.40 


8.78 


6.97 


78 


10 


3-42 


3-42 


2-57 


3-14 


5 


9.88 


8.80 


4-51 


7-73 


5-43 


105 


10 


5.48 


5-14 


2.74 


4-45 





13-71 


11.31 


6.17 


10.39 


7.42 


Class II 
























(16) 25-1 


5 


7-03 


1. 71 


9.08 


8.06 





14.91 






11-43 


9-74 


(16) 74-1 


15 


4-97 


.68 


7-54 


6.26 





12.80 






9.81 


8.03 


(16) 91-1 


2 


13.20 


13-37 


3-61 


10.06 





16.63 






12.76 


II. 41 


(16) lOO-I 


5 


5-83 


5-31 


3-42 


4-85 





17.71 






13-58 


9.16 


Class III 
























(16) 175-1 


2 


16.19 


9-94 


12.34 


12.82 





20.00 


16.97 




15-86 


14-34 


Class IV 
























(15) 25-7 


2 


9.60 


5-14 


9.60 


8. II 





15-54 


10.91 


8.05 


11.50 


9.80 


(15) 25-8 


2 


10.63 


6.34 


7.71 


8.23 





15.60 


10.57 


6.46 


10.87 


9-55 


(15) 74-1 


2 


12.17 


8.91 


10.48 


10.52 





13-88 


8.91 


6.11 


9.60 


10.06 


(15) 74-2 


5 


10.28 


10. II 


7-03 


9.14 





II. 14 


9-31 




10.22 


9.68 


(15) 78-2 


50 


3-08 


2.40 


4.11 


3.20 


10 


10. II 


8.51 


6.74 


8-45 


5-82 


(15) 78-5 


50 


2.57 


8.40 


1.20 


2.86 


10 


10.34 


8.97 


8-74 


9-35 


6.10 


Class V 
























(15) 25-8-2 


20 


7-37 


8.05 


II. 14 


8.85 





13-43 






10.30 


9-57 


(15) 74-1-2 


20 


7-03 


7-37 


12.34 


8.91 


5 


11.94 






9.16 


9-03 


(15) 74-2-2 


20 


6.00 


5-14 


10.80 


7.81 


5 


11.60 






8.89 


8.30 


(15) 74-4-2 


20 


6.51 


9-77 


10.97 


9.08 


5 


11.03 






8.46 


8.77 


(15) 78-1-2 


30 


15-14 


12.51 


10. II 


9-25 


5 


12. II 






9.29 


9.27 


Class VI 
























25 


98 


I — 


I — 


I — 


I — 


75 


1-65 


2.00 


3-42 


2.35 




67 


100 














95 


.28 


.28 


•51 


-35 




74 


100 














80 


1.02 


2-34 


3-31 


2.22 




78 


100 














90 


-17 


•51 


.80 


-51 




100 


99 


I — 


I — 


I — 


I — 


50 


1.48 


1.88 


5-43 


2.93 




105 


98 


I — 


I — 


I — 


I — 


50 


2.85 


2.62 


6.51 


4.01 




174 


100 














95 


.22 


-34 


1.48 


.68 




175 


100 














99 




.22 


2.51 


.91 





STAKMAN, HAYES, AAMODT AND LEACH : FLAX WILT. 29/ 

Certain general facts are apparent from a study of these results. 
The most important fact brought out is that the selections which were 
most resistant at University Farm behaved in the same manner at 
the \\'aseca substation. This is important because it has been shown 
that varieties of plants resistant to certain diseases in a given locality 
are not always resistant in others, due to the presence of a different 
strain of the pathogene. It is of interest to note in Table i that the 
two selections listed at North Dakota Resistant No. 13 and North 
Dakota Resistant No. 52 were very susceptible at the University 
Farm. These varieties had been grown several years since their 
original distribution so it is possible that they were somewhat mixed. 
It is possible also that a variety retains its resistance only when grown 
continuously in the presence of the disease-producing organism. 
'More extensive studies are being made to determine this and also to 
determine the possible occurrence of different strains of the fungus. 
It is apparent, however, that the same strain of Ftisarium lini is pres- 
ent at both Waseca and University Farm, Minn. 

It will no doubt be noticed that in series I to III at Waseca there 
was a progressive decrease in yield. This was undoubtedly due to 
the poorer soil on this side of the field. In some cases there was not 
enough seed available for more than one or two series. In the final 
averages the yields for these selections are recomputed on the basis of 
the average decrease in the selections which were grown in all three 
replications. The results as given indicate that this method of com- 
putation is fairly reliable. 

That actual results have been obtained is readily seen by comparing 
the average yields of the selected varieties with those of the nonse- 
lected varieties. The differences in wilt resistance are shown in 
Plate 9. 

It is quite apparent that, although good results can be obtained by 
the bulk method of selection, the individual plant method gives a 
more uniform product. 

SEED PLOT METHOD FOR PRACTICAL PURPOSES. 

It is evident that by careful selection it is possible to produce a 
good crop of flax on heavily infected flax-sick soil. The question is, 
how can this fact be best utilized in practice. The production and use 
of wilt-resistant varieties of flax should be brought into general prac- 
tice as soon as possible unless the production of flaxseed is to decrease 
continually. The first essential of any crop improvement system is 
that it be as simple as possible. With this in view a seed-plat method 



298 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY, 

is recommended for the use of the flax producer. The highest yield- 
ing selections already produced should be increased and distributed 
to farmers as has already been done in North Dakota. The seed for 
field use can then be grown on a small plat of soil known to be in- 
fested with wilt. This plat of fliax-sick soil may then constitute a 
permanent seed plot. Sufficient seed should be saved from the seed 
plat each year to plant the following year, the remaining seed being 
sown in the general field. It is believed that if this plan were exten- 
sively adopted the losses from flax wilt could very largely be elimi- 
nated and flax production eventually could be restored to norr.:-:^.!. 

Literature Cited. 

1. BoLLEY, H. L. Flax wilt and flax sick soil. N. Dak. Agr. Expt. Sta. Bui. 

50. 1901. 

2. . Flax and flax seed selection. N. Dak. Agr. Expt. Sta. Bui. 55. 1903. 

3. . Some results and observations noted in breeding cereals in a specially 

prepared disease garden. In Proc. Amer. Breeders Assoc., 5 : 177-182. 
1909. 

4. EssARY, S. H. Notes on tomato diseases with results of selection for re- 

sistance. Tenn. Agr. Expt. Sta. Bui. 95. 1912. 

5. Jones, L. R., and Oilman, J. C. The control of cabbage yellows through 

disease resistance. Wis. Agr. Expt. Sta. Research Bui. 38. 1915. 

6. Orton, W. a. The wilt disease of cotton and it's control. U. S. Dept. Agr., 

Div. Veg. Phys. Path. Bui. 27. 1900. 

7. . The development of farm crops resistant to disease. U. S. Dept. Agr. 

Yearbook for 1908, p. 453-464. 1909. 



COOK : EXPERIMENTS IN SPACING COTTON. 



299 



EXPERIMENTS IN SPACING COTTON.^ 
O. F. Cook. 

Knowledge of the structure and habits of a plant is essential to a 
full understanding of cultural requirements. It is not sufficient to 
perform experiments, or to give directions. Established opinions and 
customs are not changed until the underlying facts and relations are 
brought clearly before the mind. A theory may become dominant, 
like that of wide spacing of cotton, even without facts to support it. 
Belief governs action in agriculture no less than in other fields of 
human effort. New facts or principles are not fully applied until they 
are generally and thoroly understood, and the previous opinions are 
seen to have been defective. 

General reasoning that may be applicable to other crops is distinctly 
out of place with cotton, because the plant has habits of its own. 
There is no direct or regular relation between the size of cotton plants 
and the yield of lint and seed, but very often a contrary or inverse 
relation, smaller harvests from larger plants. The key to this paradox 
is that the main stalk of the cotton plant produces two distinct kinds 
of branches, one kind able to bear an early crop of bolls, the other not. 
If growth is too luxuriant at first vegetative branches are developed 
at the expense of fruiting branches. 

Rank growth of young cotton plants also leads to blasting and 
shedding of floral buds or young bolls, and even to general abortion 
of the early fruiting branches, in cases where young plants that have 
behaved normally in the first weeks pass into a very luxuriant condi- 
tion, in warmer weather. The physiological state of plants making 
rapid vegetative growth not only is unfavorable to the setting of fruit 
but apparently involves injury and death of the fruiting parts, even 
when other unfavorable conditions are not encountered. 

Chances of an early crop are much better with plants of moderate, 
restricted growth and only a central or main stalk, than with the large 
plants that develop numerous vegetative branches or side stalks. 
Plants that produce only a single stalk not only are in a better physio- 
logical state for producing and retaining floral buds and young bolls 

^ Contribution from the Bureau of Plant Industry, United States Department 
of Agriculture, Washington, D. C. Received for publication May 5, 1919. 



300 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



early in the season, but cultural conditions in single-stalk fields are 
also more favorable for bringing the early bolls to maturity. In- 
jurious crowding is avoided by suppressing the side stalks, altho the 
plants are more numerous and stand closer together in the rows. The 
rather narrow, upright form of the single-stalk plants permits the 
space between the rows to remain open, so that the lower fruiting 
branches continue to be reached by the light and heat of the sun. 
When the plants grow large and have strong vegetative branches that 
fill the space between the rows, the lower fruiting branches are 
thrown into deep shade and most of the early bolls are aborted. 

Vegetative branches not so large or so numerous as to interfere 
directly with the development of early bolls may still be injurious in- 
directly. Overgrown plants are more likely to be checked by drouth, 
which is another cause of blasting and shedding of buds or young 
bolls. In some experiments large spreading plants were conspicuously 
wilted in the middle of the day, while small plants in adjacent rows 
remained turgid. Such differences of behavior explain the cultural 
superiority of single-stalk plants, and the advantage of suppressing 
or avoiding the development of the vegetative branches. Usually this 
can be accomplished by the simple expedient of leaving the plants 
closer together in the rows, and thinning them later than was formerly 
considered advisable. The system of controlling the vegetative 
branches has been described as single-stalk cotton culture.^ 

The experiments that have been made under a very wide range of 
conditions in different parts of the cotton belt leave no doubt that the 
principle of control of branching can be used to general advantage, 
but no uniform directions can be given that would insure the best 
results under all conditions. To expect this would be as reasonable 
as prescribing universal methods for other farm operations. As 
already explained, the single-stalk system is flexible and readily 

2 For more detailed accounts of structural and cultural features see publica- 
tions of the U. S. Department of Agriculture, especially the following: Dimor- 
phic Branches of Tropical Crop Plants, Bur. Plant Indus. Bui. 198; Arrange- 
ment of Parts in the Cotton Plant, Bur. Plant Indus. Bui. 222; the Branching 
Habits of Egyptian Cotton, Bur, Plant Indus. Bui. 249 ; Morphology of Cotton 
Branches, Bur. Plant Indus. Cir. 109; A New System of Cotton Culture, Bur. 
Plant Indus. Cir. 115; Abortion of Fruiting Branches in Cotton, Bur. Plant 
Indus. Cir. 118; A New System of Cotton Culture and Its Application, Farmers' 
Bulletin 601; Single-Stalk Cotton Culture, Bur. Plant Indus. Doc. 1130; 
Brachysm a Hereditary Deformity of Cotton and Other Plants, Jour. Agr. 
Research, 3 : 387 ; Single-Stalk Cotton Culture at San Antonio, Texas, Dept. 
Bui. 279; Experiments with Single-Stalk Cotton Culture in Louisiana, Arkansas 
and North Carolina, Dept. Bui. 526. 



cook : experiments in spacing cotton. 301 

adapted .to circumstances. Bad weather, lack of labor or other ob- 
stacles may interfere with thinning at an ideal time, but whenever the 
work is done the principle of control needs to be taken into account. 

Practical familiarity can be gained by simple comparisons of 12- 
inch and 6-inch spacings in alternate blocks of 4 or 5 rows, with both 
spacings thinned at the same time, preferably when the plants are 
from 6 to 10 inches tall. The number and size of the vegetative 
branches developed in the 12-inch spacing will serve as a measure of 
luxuriance for the local conditions, while the 6-inch rows will show 
more restriction and control. If vegetative branches are not devel- 
oped in the 12-inch spacing, it will be evident that thinning was de- 
ferred much longer than was necessary to suppress vegetative 
branches in the 6-inch rows, and that earlier thinning might have in- 
creased the yields of these rows. It is only in extreme conditions, as 
on plants forced into rapid growth after being checked severely by 
cold or dry weather, that large vegetative branches develop in 6-inch 
spacings, unless the stands are irregular. Loss of the terminal bud 
often results in the development of several vegetative branches, but 
if thinning is not done too early the injured plants are easily recog- 
nized and removed. 

Thick stands require earlier thinning, while open stands sometimes 
yield better without thinning. Cotton of moderate growth may be 
thinned earlier than rank-growing cotton, but very early thinning, 
before the plants are 5 or 6 inches high, exposes the seedlings pre- 
maturely, and often injures the crop by reducing the stand or by in- 
creasing the number of plants crippled by leaf cut or injured by 
insects. Late planted cotton usually needs to be left closer to the 
rows and thinned at a more advanced stage of growth than early 
plantings, often not until the plants are 10 or 12 inches high, or even 
15 or 18 inches, depending upon the stand and other conditions of 
growth. Another general relation is that of time of thinning to the 
spacing that should be used. If the spacing is to be close there is less 
need to defer thinning, but if thinning is much deferred it becomes 
more necessary to use close spacing. Otherwise the yield may be 
seriously reduced, especially under short-season conditions. 

By planting in hills and thinning gradually, plants usually can be 
kept in the single-stalk form at any distance apart, i foot, 2 feet, or 
3 feet, but closer spacings are preferable. Not how many feet, but 
how many inches apart the plants should be is the practical question 
to be determined by local experiments. Fortunately such exper- 
iments are not difficult, and can be tried in ordinary fields of cotton, 
with changes only in thinning and spacing. 



302 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

In single-stalk culture of Egyptian cotton under long-season con- 
ditions in Arizona a wide range of spacings can be used, any of them 
better than uncontrolled branching. Yields of over a bale per acre 
have been obtained from single-stalk plants 2 feet apart in the rows, 
and also from plants only 4 inches apart, as well as from several inter- 
mediate spacings, 6 inches, 8 inches, 12 inches, and 18 inches, but 
usually with distinct advantages for the closer spacings, when com- 
parisons are made in adjoining plots. Even with rows only 2.5 feet 
apart and the plants spaced at 4 inches in the rows, the yield was 
large. Rows 3.5 feet apart with plants 6 to 8 inches apart in the rows 
has been the most successful arrangement used thus far on a large 
scale, but in the more luxuriant fields the rows meet across the lanes 
and many of the lower fruiting branches are smothered. For condi- 
tions of rank growth experiments are now to be made with rows 4 
feet apart and plants 4 inches apart, as an arrangement likely to give 
somew^hat more effective control of growth and branching in the early 
stages, and less crowding between the rows. 

Wide spacing and early thinning continue to be tried by farmers 
who have not had experience with Egyptian cotton under the Arizona 
conditions, but crowding is only made worse when the branching is 
not controlled. Fields of overgrown plants become veritable jungles 
of dense foliage and heavy wood limbs, with low yields of fiber, not 
of the best quality and difificult to pick. Thinning first to 4 inches will 
allow more space to be given later in the season, after the stage of 
producing vegetative branches is past, by pulling out every second or 
third plant, if experiments prove that sufficient advantage can be 
gained to justify the additional labor. With ordinary stands thinning 
to 4 inches may be done when the plants are from 6 to 10 inches tall^ 
and further thinning at any later stage, when it appears that the plants 
are becoming crowded to an extent that is likely to reduce the yield 
or impair the quality of the fiber. 

With upland cotton in Texas there may not appear to be the same 
need of controlling the growth of the plants by cultural means, since 
growth is often restricted by cold or dry weather, but it is essential 
that bolls be set and retained early in the season since drouths or boll 
weevils usually interfere with the production of a late crop. The 
period of setting bolls may be very short, as in the experiments de- 
scribed by Rowland M. Meade in 1914 at San Antonio, Texas, when 
nearly all of the bolls were set within about 25 days. In this case 
more than twice as much cotton was produced from small single-stalk 
plants standing only 6 to 8 inches apart in the rows than from large 



cook: experiments in spacing cotton. 



303 



spreading plants thinned early to 2 feet apart that developed large 
vegetative branches. Tho results would not differ so widely in longer 
fruiting seasons, there is no reason to expect in any year that more 
cotton per acre can be produced on large spreading plants. Dif- 
ferences of 20 to 50 percent in yield are not infrequent, and afford 
sufficiently striking examples of the utility of branch control. 

Earliness, in the practical sense of increased production in shorter 
fruiting periods, cannot be determined from first dates of flowering 
or of opening of bolls, but is shown by the setting of more bolls and 
the maturing of a larger crop. Nevertheless, any differences of be- 
havior that can be observed and recorded are likely to be of interest 
or of practical use in tracing effects back to their causes and thus 
learning how the principle of control may be applied to the best ad- 
vantage. Features that can be used for such comparisons are the size 
or rate of growth of the main stalks, the numbers, lengths, and posi- 
tions of the two kinds of branches, the dates and rates of flowering 
and opening of bolls, numbers of bolls with 3, 4 or 5 locks, and 
weights of seed cotton from the different classes of bolls, in addition 
to the lint and seed characters which usually receive attention. 

Control of branching may be considered successful when com- 
parisons show practical advantages in larger yields or earlier ripening 
of the crop, but this does not prove that the full possibilities of the 
system have been realized in any particular test. That partial control 
or over-control may be better than no control, only shows that it is 
desirable to go further and determine the most effective utilization of 
the principle, thru local experiments and comparisons of behavior. 
It is only in this way that adequate discrimination and skill can be 
developed in the handling of different varieties and types of cotton 
under the wide range of cultural and seasonal conditions that are 
encountered in practice. 



304 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



EFFECT OF WOUNDS ON LOSS OF WEIGHT OF POTATOES.^ 

O. Butler. 

We are always told that. in harvesting potatoes care should be ex- 
ercised not to cut or bruise them unnecessarily, as not only is their 
market value much reduced when they are roughly handled but they 
also lose weight more rapidly than uninjured tubers. This latter 
effect of rough handling has not been particularly stressed to my 
knowledge, but, as the following experiment shows, it is nevertheless 
worthy of attention. 

Tubers of Triumph, Early Rose, and Rural New Yorker potatoes 
were carefully selected for freedom from wounds and bruises and 
divided into two equal series, which were respectively denoted by the 
letters A and B. In series A a small slice, hardly more than skin 
deep, was cut off each tuber; while in series B the tubers were not 
damaged in any way and thus served as a measure of the loss due to 
slight wounding. The temperature of storage was 8° to 10° C. and 
the experiment was allowed to run 11 1 days. The results obtained 
are presented in Table i. 

Table i. — Effect of wounding on loss of weight of potatoes. 



Loss of weight after — 



Variety and method of treatment. 


8 

days. 


16 
days. 


days. 


days. 


40 

days. 


48 
days. 


66 
days. 


days. 


days. 


III 
days. 




Per- 


Per- 


Per- 


Per- 


Per- 


Per- 


Per- 


Per- 


Per- 


Per- 




cent. 


ce fit. 


cent. 


cent. 


cent. 


cent. 


cent. 


cent. 


cent. 


ce7it. 


Triumph: 
























0.48 


1.03 


1-45 


1.92 


2.30 


2.75 


3.87 


5.22 


7.12 


9.21 


Tubers cut 


1.57 


2.19 


2.65 


3.22 


3.65 


4.II 


5-45 


7. II 


8.94 


II. 81 


Early Rose: 
























0.56 


1.08 


1.52 


1.97 


2.39 


2.62 


3-36 


4.21 


5.10 


6.23 




1.30 


2.25 


2.73 


3-37 


3-90 


4-30 


5-36 


6.27 


7-54 


9.08 


Rural New Yorker: 
























0.72 


I-I3 


1.67 


2.22 


2.72 


3.17 


4.07 


4.98 


6.25 


7-30 


Tubers cut 


I.61 


2.49 


3.02 


3-72 


4.42 


4.67 


5.70 7.06 


8.20 


9.61 



As will be seen from a consideration of Table i, the loss of weight 
due to wounding, while rapid during the first week, at first markedly 
and then slowly decreases thereafter. The increased loss of weight 



^ Contribution from the New Hampshire Agricultural Experiment Station, 
Durham, N. H. Received for publication June 23, 1919. 

t 




BUTLER : LOSS OF WEIGHT OF POTATOES. 3O5 

due to the wounding does not become extinct, however, until after 79 
days, when the ratio between loss of weight of non-cut and cut tubers 
assumes a constant value. 

The complete healing of a wound and the return of the potato to 
a normal condition is rather a slow process at a storage temperature 
of 8° to 10° C. and one would expect that storing wounded potatoes 
at a temperature more suitable for rapid healing would cause the 
ratio between loss of weight from cut and non-cut tubers to assume a 
constant value much more promptly. In effect as may be gathered 
from Table 2, healing occurs promptly at 20° C. and loss of weight is 
relatively less important. 



Table 2. — Effect of temperature on the rapidity of healing of wounded Triumph 
potatoes, the loss of weight of non-cut tubers being taken as unity. 



Tempera- 
ture of 
storage. 


Duration of experiment. 


8 days. 


16 days. 


32 days. 


40 days. 


48 days. 


4 days. 


79 days. 


95 days. 


°c. 

20 

8-10 


1.92 
3-27 


1.49 
2.12 


I.41 
1.67 


1.24 
■1.58 


1.25 
1.49 


1. 16 
1.40 


1.24 
1.36 


I.31 
1.25 



Advantage cannot well be taken of this fact in practice, however, 
as the saving realized would amount to only a half percent as will be 
seen from the following figures, a duration of storage of iii days 
being assumed. 

Percent, loss of weight. 

Wounded potatoes stored at 20° C. for 32 days, then placed 

in storage at 8-10° C 11.25 

Wounded potatoes stored directly at 8-10° C 11. 81 

Sound tubers stored at 8-10° C 9.21 

It is clear that if slight wounding occasions a loss of more than 2 
percent, which is not in itself negligible, larger losses will follow 
rough handling. Potatoes should therefore be carefully harvested 
and care should be exercised neither to cut nor unnecessarily bruise 
them for, as we have seen, tubers are more sensitive to injuries than 
would be anticipated from their general solidity. 



306 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



AGRONOMIC AFFAIRS. 
MEMBERSHIP CHANGES. 

The membership of the Society reported in the May number was 
537. Since that time 14 new members have been added and 10 have 
resigned, making a net gain of 4 and a present membership of 541. 
The names and addresses of the new members, the names of those 
who have resigned, and such changes of address as have been re- 
ported follow. 

New Members, 

Baldwin, I. L., Agr. Expt. Sta., Purdue Univ., La Fayette, Ind. 

Bayles, John J., Experiment Farm, Coly, Kans. 

Ching, K. a., Agr. Expt. Sta., Honolulu, Hawaii. 

Chung, H. L., Agr. Expt. Sta., Honolulu, Hawaii. 

Davis, L. Vincent, 1248 S St., Athens, Ga. 

EsPLiN, Alma, Cedar City, Utah. 

FoRTUN, Gonzalo M., Calle g No. 5, Santiago de las Vegas, Cuba. 
Gonzalez, Joaquin J., Apalit, Pampanga, Philippine Islands. 
LeWorthy, G. E., School of Agriculture, Morrisville, N. Y. 
Miller, Justus R., Dept. Agr., Parliament Bldg., Toronto, Canada. 
Moss, W. A., Experiment Farm, Felt, Idaho. 
Nelson, A. L., Cheyenne Field Station, Cheyenne, Wyo. 
Stone, Benj. C, 174 Second Ave., New York, N. Y. 
White, C. L., Box 137, Clinton, Mo. 



Allen, Edward R., 
Brewer, Herbert C, 
Curtis, H. P., 
Graber, L. F., 



Members Resigned. 

Holt, L. V., 
Jensen, L. N., 
Roudebush, R. I., 

Changes of Address. 



Paxton, Glen E., 
Stephenson, R. E., 
Van Alstine, E. 



Bauer, F. C, 932 W. Johnson St., Madison, Wis. 
BiRCHARD, F. J., Postal Sta. B., Winnipeg, Man., Canada. 
Burdick, R. T., College of Agriculture, Fort Collins, Colo. 
Burgess, Paul S., College of Agriculture, Berkeley, Cal. 
Carleton, M. a.. Cosmos Club, Washington, D. C. 
Chapman, James E., Box 84, Route 3, Anoka, Minn. 
Clark, Chas. F., Presque Isle, Maine. 

Clark, Chas. H., Albert Dickinson Co., Lock Drawer 788, Chicago, 111. 
Clemmer, H. J., Experiment Farm, Dalhart, Texas. 

Fippin, E. O., Agr. Bureau, Lime Association, Mather Bldg., Washington, D. C. 
GiLLis, M. C, R. F. D. 4, South Bend, Ind. 



AGRONOMIC AFFAIRS. 



Granowsky, Alex., P. O. Box 272, Mancos, Colo. 

Griffee, Fred, Agronomy Div., University Farm, St. Paul, Minn. 

HowAT, John, Huntsville, Mo. 

Kenx.vrd, F. L., Moscow, Idaho. 

Kidder, A. F., Agr. Expt. Sta., Baton Rouge, La. 

LaTourette, Lyman D., 1324 East Fillmore St., Phoenix, Ariz. 

LeClerc, J. A., Miner-Holland Milling Co., Wilkes-Barre, Pa. 

Love, Russell M., Brooklyn, Pa. 

Lund, Viggo, Maribo Sugar Factory, Maribo, Denmark. 

Newton, R., College of Agriculture, Edmonton (So.), Alta., Canada. 

Pendeleton, Robert L., Asst. Dir. of Agriculture, Gwalior, India. 

Riley, J. A., Coast Experiment Station, Summerville, S. C. 

Smith, Nelson S., School of Agriculture, Vermilion, Alta., Canada. 

Smith, Oliver, 6 Cedar Parkway, Chevy Chase, Md. 

Stemple, F. W., Aurora, W. Va. 

TuTTLE, H. Foley, Room loio, iii W. Monroe St., Chicago, 111. 
Westley, Roy O.. Farm Crops Dept., Wash. State Col., Pullman, Wash. 
Winters, N. E., Extension Agronomist, Charlotte, N. C. 
Woodard, John, Hull Laboratory, Univ. of Chicago, Chicago, 111. 

NOTES AND NEWS. 

R. P. Bean has been appointed superintendent of the newly estab- 
lished State irrigation substation at Prosser, Wash. 

Guy Potter Benton, educational director of the American Army of 
Occupation in Germany, has resigned as president of the University 
of Vermont. 

J. F. Block, formerly agricultural engineer with the irrigation 
branch. Department of the Interior, Calgary, Alta., is now assistant 
superintendent of the experiment station at Rosthern, Sask. 

Chas. H. Clark, formerly in charge of flax seed investigations in 
the U. S. Department of Agriculture, resigned September i to accept 
a position with the Albert Dickinson Company, wholesale seed mer- 
chants, with headquarters in Chicago. 

Thomas P. Cooper, director of the Kentucky station, has also been 
appointed director of extension, with T. R. Bryant and Geofifrey 
Morgan as assistants. 

J. D. Eggleston, for the past several years president of the Vir- 
ginia Polytechnic Institute, resigned July i to become president of 
Hampden-Sidney College. He was succeeded by Julian A. Burruss, 
formerly president of the State Normal School at Harrisonburg, Va. 

The experimental work with fertilizers and forage crops formerly 
conducted at McNeill, Miss., with E. B. Ferris as assistant director in 
charge, has been transferred to Poplarville. 



308 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



R. L. Hensel, of the Forest Service, has been appointed associate 
professor of pasture management in the Kansas station, where he 
will have charge of pasture investigations which are planned to make 
better use of the grass lands of the State. 

E. A. Hodson, assistant professor of agronomy in the Delaware 
college, resigned June 30 to accept a position with the Arkansas 
station. 

Jesse M. Jones, director of extension in Virginia, has resigned to 
take charge of the agricultural and industrial department of the Sea- 
board Air Line Railway, and has been succeeded by John R. Hutche- 
son, formerly assistant director of extension. 

F. L. Kennard, county agent in Whitman Co., Wash., has resigned 
to engage in the seed business in Moscow, Idaho. 

A. F. Kidder has resigned as professor of agriculture in the Louis- 
iana college to become agronomist and assistant director of the 
Louisiana station at Baton Rouge. 

F. G. Krauss, superintendent of the extension division in the 
Hawaii Federal station, has been placed in charge of the Haleakala 
homestead demonstration farm in addition to his other duties. 

' Forest W. McGinnis is now assistant professor of agronomy and 
assistant agronomist of the Minnesota college and station. 

Wallace Macfarlane, formerly chemist of the Oklahoma station, 
is now in charge of soil fertility investigations in the divisions of 
agronomy and chemistry of the Hawaii Federal station. 

. H. A. Morgan has been appointed president of the University of 
Tennessee, effective July i. in addition to his duties as dean and 
director. J. D. Hoskins, dean of the college of liberal arts, is as- 
sistant to the president; C. A. Willson, animal husbandman, is as- 
sistant dean of the college of agriculture ; and C. A. Mooers, chemist 
and agronomist, is assistant director of the station. 

C. L. Newman has resigned as head of the department of agronomy 
of the North Carolina college and station to accept a position with the 
Federal Board of Vocational Education. 

James R. Riggs, an Indiana farmer and business man, is now as- 
sistant secretary of the Federal Department of Agriculture. 

George Severance, vice dean of the Washington college of agri- 
culture, is head of the newly established department of farm man- 
agement in that institution. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. II. November, 191 9. 



SYNTHETIC PRODUCTION OF HIGH-PROTEIN CORN IN 
RELATION TO BREEDING.^ 

H. K. Hayes and R. J. Garber. 

Introduction. 

A standard plan of procedure has been developed for the small 
grain breeder by the application of Mendel's principles and thru 
studies in field plot technic. Minor variations in methods used by 
different investigators occur, but fundamental principles are well 
known. 

With corn improvement there is no such uniformity of technic. 
Some breeders favor the use of the corn score card as a means of 
isolating higher yielding varieties (12).^ A much larger number 
believe the score card is of no value in isolating higher yielding varie- 
ties (18, 23, 29). It is recognized that the corn shows promote an 
interest in crop production (13). However, this does not seem a 
good reason for teaching the corn grower that ear-type selection may 
l)e expected to increase yield. Many breeders believe that the ear- 
to-row test is very valuable and some workers believe it is the only 
method of isolating a higher yielding variety (20). Others doubt 
the value of ear-to-row breeding for farmers. They also question 
the value of its continued use by the investigator (18, 21, 23). Field 
experiments have not always been carefully planned. For example, 
some workers have made comparisons of varieties and strains by 

1 Published with the approval of the Director as Paper No. 178 of the Journal 
Series of the Minnesota Agricultural Experiment Station, University Farm, 
St. Paul, Minn. Received for publication July 26, 1919. 

2 Reference is to "Literature cited," p. 317. 

309 



No. 8. 



3IO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

growing only a single row of each sort. Two errors are thus intro- 
duced, one due to competition between different varieties (19), the 
other to soil heterogeneity. This has led to the use of replicated plots 
each consisting of several rows. 

A recent discussion of the reason for conflicting results of corn 
experiments is interesting. Carrier (i) has emphasized the imme- 
diate effect of foreign pollen on endosperm size and questions the 
reliability of varietal tests. This without doubt is one cause of error, 
for corn is largely cross pollinated (10, 28). There is certainly as 
much opportunity in plot studies for a variety to be pollinated with 
itself as with another variety. Thus, even tho yields are sometimes 
increased 5 to 10 percent due to the immediate effect of foreign pollen, 
it seems very doubtful if this would cause a difference in final yields 
of more than 2 percent in plot tests. There is another reason why a 
mixture of seed of varieties should on the average yield more than 
pure varieties (i). As seasonal conditions vary, a mixture of dif- 
ferent sorts would contain some genotypes which were adapted for 
the season in question. The average of three years' data obtained 
at the Minnesota station indicates that mixtures are not always of 
great value. Two plots were used for each variety, each plot con- 
sisting of several rows. The respective average yields in bushels per 
acre of Minnesota No. 13, Minnesota No. 23, Mercer, and a mixture 
of equal quantities of seed of No. 13, No. 23 and Mercer are 46.1, 
39,1, 44.5, and 46.3. Yields were computed after allowing the corn 
to become crib dry. It will be noted that the mixture yielded as much 
as the highest yielding variety, and gave an increase of nearly 7 per- 
cent over the average of the three varieties. Thus the method seems 
worthy of further trial. 

The effects of inbreeding and crossbreeding on development go far 
toward explaining many of the conflicting results of corn studies. 
Selection modifies the genotypic nature of a variety. Artificial self- 
fertilization accomplishes a similar result in a much more rapid man- 
ner. The same fundamental principles, however, apply in both cases. 
The present paper is a discussion of inbreeding and crossbreeding in 
its relation to methods of corn improvement. 

RESULTS OF SELF-FERTILIZATION IN CORN. 

The results of self-fertilization (4, 5, 6, 15, 24, 25) in corn are well 
known and need be only briefly summarized. It is now recognized 
that self-fertilization is not in itself harmful. By continued self- 
fertilization strains are isolated which are homozygous for all or 



HAYES & GARBER: BREEDING HIGH-PROTEIN CORN. 3II 

nearly all of their characters. From a theoretical standpoint the 
first year of self-fertilization has the greatest effect and the strain 
gradually approaches the homozygous condition. Eight to ten years 
of continuous self-fertilization should be sufficient to produce strains 
which are homozygous for all or nearly all characters. Since only 
single plants are used as parents for each generation, it is theoretically 
possible for many years to elapse before homozygosity is reached. 
It is equally possible to produce a homozygous sort in a much shorter 
])eriod. 

Near homozygous strains are easily recognized. All plants approach 
uniform habit for morphological characters as well as in size and 
vigor. Crosses between such self-fertilized strains are uniform and 
very vigorous as a rule. Remarkable yields have been obtained from 
such crosses. 

It was easily recognized that vigor in corn was closely related to 
the heterozygous condition. The explanation of the reason for these 
results was not entirely satisfactory. A recent hypothesis is of much 
interest (14). Vigor in corn is explained as due to the presence of 
certain necessary growth factors. Self-fertilization isolates sorts 
which are homozygous for certain of these factors. The cross which 
yields the highest is supposed to contain the largest number of factors 
necessary to most vigorous development. Each growth factor pro- 
duces nearly as great an effect when heterozygous as when homo- 
zygous. Linkage is used to explain why no selfed sort has been 
obtained with as high yielding ability as that of crosses. Whether 
this explanation is essentially correct can only be determined from 
further investigation. It satisfactorily accounts for all the facts in- 
volved and helps the breeder to correlate results. An appreciation 
of these facts has considerable bearing on the technic of breeding. 

There are three possible means of utilizing increased vigor from 
crosses. These will be considered under the headings of (a) first- 
generation variety crosses; (b) first-generation crosses between self- 
fertilized strains; and (c) synthetic production of a variety by self- 
fertilization, crossing, and subsequent selection. 

FIRST-GENERATION VARIETY CROSSES, 

A suggestion for utilization of first-generation variety crosses was 
made by Morrow and Gardner (22) in 1893. Many comparisons of 
such varietal crosses have been made due to a growing appreciation 
of the results from self-fertilization and crossing. These results 
have shown that, on the average, first-generation crosses may be ex- 



312 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY, 



pected to yield more than the average of the parents (3, 8, 12, 17). 
Some few tests have given negative results. As an example, Kiessel- 
bach (18) found varietal crosses with Hogue Yellow Dent as the 
male parent were no better than the parental averages. He concludes 
that there is no value in F^^ crosses between adapted varieties. 

During the last four years varietal crosses have been compared 
with their parents at the Minnesota station. Minnesota No. 13 was 
used as the male parent in all cases. The adapted dent varieties, 
Rustler, Silver King, Murdock, and Minnesota No. 23, have been 
crossed with Minnesota No. 13. Longfellow, Smutnose, Mercer, and 
King Phillip have been used as flint parents. Crosses of Minnesota 
No. 13 with Rustler, Minnesota No. 23, and Silver King have been 
compared with their parents for a 4-year period, while the Murdock 
X Minnesota No. 13 cross has been tested for three years, Longfellow 
X Minnesota No. 13 for four years, and King Phillip X Minnesota 
No. 13 and Smutnose X Minnesota No. 13. for two years. Average 
results are presented in Table i. 



Table i 



-Yields of first-generation crosses and their parents.*^ 



Variety. 


Yield on a per- 
centage basis 
with Minn. No. 
13 as 100. 


Minn. No. 13 


100. 


King Phillip 


100. 


King Phillip X No. 13 


II9.9 




100.5 


Longfellow X No. 13 


119. 6 


Smutnose 


no. 8 


Smutnose X No. 13 


127.6 


Minn. No. 23 


96.7 



Variety. 



Yield on a per- 
centage basis 
with Minn. No. 
13 as ICQ. 



Minn. No. 23 X No. 13. 

Rustler 

Rustler X No. 13 

Silver King 

Silver King X No. 13. . . 

Murdock 

Murdock X No. 13 ... . 



no. 9 
112. 1 
112. 4 
100.9 
106.7 
80.3 
101.6 



« See Minn. Agr. Expt. Sta. Bui. 183. 



The varieties used were selected because they were adapted for 
growing in this section of Minnesota. Remarkable increases in yield 
were obtained from the crosses between 8-rowed flints and Minnesota 
No. 13. Similar high yields have been obtained from the F.^ of flint- 
dent crosses grown at the Connecticut station. The high yield of the 
of the Minnesota No. 13-flint cross may be partially explained by 
the fact that the dent has been so closely selected to type. In inter- 
species crosses it is reasonable to suppose that two groups of growth 
factors have been brought together which differ more widely than in 
the case of intraspecies crosses. This may explain why flint-dent 
crosses are so vigorous. 



HAYES & GARBER : BREEDING HIGH-PROTEIN CORN. 3 I 3 

CROSSES BETWEEN SELF-FERTILIZED STRAINS. 

Shull (24, 25) first suggested the utilization of crosses between 
self-ferilized sorts as a means of increasing yield in corn. Many data 
have been accumulated which show that such crosses are a means 
of obtaining high yields. The chief objection to this method is that 
self-fertilized strains are of low yielding capabilities and that the 
seeds obtained from selfed lines are generally much smaller than those 
obtained from normally pollinated corn. Even though crosses be- 
tween self-fertilized lines yielded very vigorously the method has not 
seemed commercially desirable. Low yields of seed per acre would 
increase the cost of seed. Under unfavorable conditions the food 
supply of the seed might not give the young plant a vigorous start. 
This objection has been overcome by a recent suggestion of Jones 
(16). After isolating selfed strains, tests are made to determine 
which four biotypes are most desirable as parents. 

Suppose these biotypes are numbered, i, 2, 3, and 4, respectively. 
Now I and 2 are crossed, also 3 and 4, by detasseling all of one bio- 
type in each group. Seed from the plants of each detasseled biotype 
is then planted in alternate rows in an isolated plot and all of one 
combination detasseled. Seed from these detasseled rows are used 
for commercial planting. 

By this method good yields of seed can be obtained. If sufficient 
increases in yield are secured the cost of the initial work would not 
be prohibitive. 

At the Connecticut station such a cross was compared with the best 
dent variety obtained after making a careful varietal survey. The 
cross yielded 112 bushels per acre, the best dent variety only 92 
bushels. This remarkable difference shows the method deserves 
further trial. 

SYNTHETIC PRODUCTION OF A NEW VARIETY. 

The synthetic production of an improved variety by inbreeding and 
crossbreeding seems a reasonable plan. A normal variety is a mix- 
ture of many types. Undesirable characters are sometimes apparent 
altho due to heterozygosis they are frequently covered. Extreme 
instances of these are plants which lack the ability to produce chloro- 
phyll and dwarf plants. 

Emerson and East (7) have outlined a method for the production 
of high oil corn as an example of inbreeding and crossbreeding in 
variety improvement. This suggestion is based upon the fact that 
selection produces nothing new but isolates races which are pure for 
certain characters. 



314 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The remarkable selection experiments which have been carried on 
with corn at the IlHnois station are well known. By continuous selec- 
tion strains were produced which differed widely in oil and protein 
content. 

In 1896 normal corn of the variety Burr White had a composition 
of 4.70 percent oil and 10.92 percent protein. At the end of ten 
years^ selection for high and low protein and high and low oil content, 
four strains were obtained (26). In 191 5 the percentage composi- 
tion of these strains for the character for which they have been se- 
lected was 14.53 7-26 protein and 8.46 and 2.07 for oil. Castle^ 
(2) has cited these results as in opposition to the pure-line theory. 
He says, " They show that valuable new varieties are not discovered 
as the mutation theory holds, but may be created by a process of 
selection." Surface (27), however, in analyzing the Illinois results 
has maintained that they indicate that selection has isolated strains 
which were originally present in the varieties. 

One of the writers started an experiment at the Connecticut station 
in 191 1 with the purpose of learning the mode of inheritance of pro- 
tein and to determine the possibility of producing high and low pro- 
tein varieties by selfing and crossing. The method outlined seemed 
especially adapted to the production of high-protein races, since data 
indicated that low protein was a dominant character (9). This evi- 
dence came from the analysis of ears produced by plants of crosses 
between Illinois high and low protein strains and a Connecticut dent 
variety. 

In 191 5 an experiment was started at the Minnesota station for the 
purpose of trying to produce a high-protein strain of Minnesota No. 
13*. The method was to self -fertilize a number of ears and analyze 
each ear for protein. High-protein self-fertilized ears were then 
used as parents. The plan was to isolate a number of high-protein 
strains and then determine which produced the highest yields when 
crossed. The better yielding cross was then to be planted in an iso- 
lated plot and selected for vigor. No new variety is yet ready for 
distribution, but the results show that the method is reliable. 

Certain facts have been discovered in this work which, if appre- 
ciated earlier, would have been of material value, since only single 
pollinations were made for each selfed ear and as conditions were 
variable, some ears contained many more seeds than others. 

3 For Castle's recent viewpoint on the effect of selection, see Amer. Nat., 53 : 
370-375. 1919. 

* The analyses of protein presented in this paper were made by the Division 
of Agricultural Biochemistry. The protein percentages are on a dry basis. 



Journal of the American Society of Agronomy. 



Plate 10. 



D 




Average ears of strain No. 2, Minnesota No. 13 corn, selfed four years (A) ; 
Fi ears of the cross between strain 2 and strain 4 (B) ; average ears of strain 
4. Minnesota No. 13, selfed four years (C) ; and ears of Minnesota No. 13 
showing various types of ears produced (D). 



HAYES & career: BREEDING HIGH-PROTEIN CORN. 



Self -fertilized ears were obtained in 191 8 from first-generation 
crosses between high-protein strains. A direct negative correlation 
was observed between the number of seeds per ear and protein 
content. 

Table 2 shows this correlation. A, B, and K are crosses between 
different ears of the same high-protein strains. They gave very simi- 
lar results for average protein content. 



Table 2. — Correlation between number of kernels of self -fertilized ears and 
their respective percentages of protein on a dry basis. 

Protein percentages. 





lO 


10 




10 

<N 


IT) 


10 


10 


LO 


XT, 
sr~ 


LO 


10 












4 






LO 


M 




!>• 






25 


















2 






2 


75 




















I 




I 


125 














I 


3 


2 


I 


2 


9 


175 














3 


3 


4 


2 




12 


225 














2 


3 


2 




I 


8 


275 




2 




I 


I 


4 


3 


3 


I 






15 


325 


2 




I 




3 


2 


4 


3 


I 






16 


375 






I 


I 


I 






I 








4 




2 


2 


2 


2 


5 


6 


13 


16 


12 


4 


3 


67 



Correlation coefficient 



.601 ± .053. 



The correlation table and calculated coefficient show a high nega- 
tive relation between number of seeds produced per ear and protein 
content. 

There is little, if any, immediate efifect of foreign pollen on the 
protein percentage the year that a cross is made. Table 3 shows the 
average percentage of protein in selfed ears of high and intermediate 
strains and from crosses between them. 



Table 3. — Immediate effect of crossing on protein content. 



Strain No. Years selfed. 

1 4 

2 4 

3 4 

4 4 

8 4 

9 4 

Average of i or 2 X 3 or 4 

Average of i or 2 X 8 or 9 



Average protein content 
of ears (1918). 
Percent. 

14.92 

15.46 

16.76 

15.09 

12.97 

12.53 

17.14 

16.89 



3l6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

These results seem sufficient to indicate that there is Httle, if any, 
effect on protein content due to the immediate effect of polHnation. 

Since the ears produced by crossing self ed sorts contained, as a rule, 
fewer seeds than selfed parental ears, the protein content of the 
crossed ears average somewhat higher. 

An analysis was made of a composite sample of open field polli- 
nated progeny of each selfed ear. Each strain was then further 
propagated by using as a parent the selfed ear which produced a high 
average protein content. Results for the average protein content of 
the composite samples are given in Table 4. 



Table 4. — Protein content of selfed strains of Minnesota No. 13 and crosses 

between them. 


Strain No. 


1 Average protein content. - 


1916. 


1917. 


1918. 


I 


Percent. 
15-82 
14.47 


Percent. 
14.03 
13.06 
10.17 


Percent. 
15.10 
14.93 
10.25 
12.25 
12.44 
12.81 


4 


Normal No. 13 

I X 4, Fi Ear A 

I X 4, Fi Ear B 

I X 4, Fi Ear K 



The season of 1915 when -the initial self-fertilizations were made 
was very unfavorable for corn and consequently only 127 selfed ears 
were obtained. Two strains were isolated which gave much higher 
percentages of protein than normal pollinated corn. These strains 
have not varied very widely during the three years that they have 
been grown. Crosses between these two strains were made in 1917 
and individual rows were grown during the season of 1918. Even 
though the parental strains had been selfed for only two years the 
crosses were very uniform. The bulk analysis showed that the 
crosses yielded on the average a little over 2 percent more protein 
than normal pollinated Minnesota No. 13. Ears of parental strains 
2 and 4, F^ ears of the cross between these strains, and normal ears 
of Minnesota No. 13 corn are shown in Plate 10. Whether strains 
with higher protein content than the ones here presented can be iso- 
lated from Minnesota No. 13 is not yet known. 

Comparative yields from these crossed strains and Minnesota No. 
13 were obtained. The yields are based on the weight of corn ob- 
tained after storing in a heated room until January i, 1919. Normal 
pollinated Minnesota No. 13 gave a yield of 48.9 bushels per acre 
while the yields of the three F^ crosses. A, B, and K, were respectively 
51.4, 51.3, and 54.2 bushels per acre. 



HAYES & GARBER: BREEDING HIGH-PROTEIN CORN. 



These crosses were planted in an isolated plot in 191 9. Selec- 
tion on the basis of vigor will be made in the field. 

SUMMARY. 

A discussion of the effect of inbreeding and crossbreeding in rela- 
tion to corn improvement is made. The writers believe that there are 
almost unlimited opportunities of improving corn by an application 
of these principles. 

An experiment is outlined for the synthetic production of high- 
protein corn by self-fertilization, crossing, and subsequent selection. 
Three crosses between high-protein strains were studied in 191 8. 
They were compared with Minnesota No. 13 which was the original 
source of the selfed strains. They gave an increase in average pro- 
tein content of a little over 2 percent as compared with Minnesota 
No. 13 and also yielded somewhat better. 

Literature Cited. 

1. Carrier, Lyman. A reason for the contradictory results in corn experi- 

ments. In Jour. Amer. Soc. Agron., 11: 106-113. 1919. 

2. Castle, W. E. Genetics and Eugenics, p. 188-191. Harvard University 

Press, Cambridge. 1916. 

3. Collins, G. N. The value of first-generation hybrids in corn. U. S. Dept. 

Agr., Bur. Plant Indus. Bui. 191. 1910. 

4. East, E. M. Inbreeding in corn. In Conn. Agr. Expt. Sta. Rpt. for 1907, 

p. 419-428. 1908. 

5. . The distinction between development and heredity in inbreeding. 

In Amer. Nat., 43: 173-181. 1909. 

6. , and Hayes, H. K. Heterozygosis in evolution and in plant breeding. 

U. S. Dept. Agr., Bur. Plant Indus. Bui. 243. 1912. 

7. Emerson, R. A., and East, E. M. Inheritance of quantitative characters in 

maize. Nebr. Agr. Expt. Sta. Research Bui. 2. 1913. 

8. Hartley, C. P., Brown, E. B., Kyle, C. H., and Zook, L. L. Crossbreeding 

corn. U. S. Dept. Agr., Bur. Plant Indus. Bui. 218. 1912. 

9. Hayes, H. K. Corn improvement in Connecticut. In Conn. Agr. Expt. 

Sta. Rpt., 6 : 353-384. 1913. 

10. . Normal self-fertilization in corn. In Jour. Amer. Soc. Agron., 10: 

123-126. 191 8. 

11. Hutcheson, T. B., and Wolfe, T. K. The effect of hybridization on ma- 

turity and yield in corn. Va. Agr. Expt. Sta. Technical Bui. 18, p. 161- 
170. 1917. 

12. . Relation between yield and ear characters in corn. In Jour. Amer. 

Soc. Agron., 10: 250-255. 1918. 

13. HoPT, Erwin. The futility of the " pretty car " corn show. In Nebr, Corn 

Improvers' Assoc. Rpt., 9: 51-59. 1918. 

14. Jones, D. F. Dominance of linked factors as a means of accounting for 

heterosis. In Proc. Nat. Acad. Sci., 3: 310-312. 1917. 



i 



3l8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

15. . The effects of inbreeding and crossbreeding on development. Conn. 

Agr. Expt. Sta. Bui. 207. 1918. 

16. . Inbreeding in corn improvement. In Breeders' Gaz., 75: 1111-1113. 

1919. 

17. , Hayes, H. K., Slate, W. L., and Southwick, B. G. Increasing the 

yield of corn by crossing. In Conn. Agr, Expt. Sta. Rpt. for 1916, p. 
323-347. 1917. 

18. KiEssELBACH, T. A. Reccnt developments in our knowledge concerning 

corn. In Nebr. Corn Improvers' Assoc. Rpt., 7: 15-42. 1916. 

19. . Studies concerning the elimination of experimental error in com- 
parative crop tests. Nebr. Agr. Expt. Sta. Research Bui. 13. 1918. 

20. LovE, H. H., and Wentz, J. B. Correlation between ear characters and 

yield in corn. In Jour. Amer. Soc. Agron., 9: 315-322. 1917. 

21. Montgomery, E. G. Experiments with corn. Nebr. Agr. Expt. Sta. Bui. 

112. 1909. 

22. Morrow, G. E., and Gardner, F. D. Field experiments with corn. 111. 

Agr. Expt. Sta. Bui. 25, p. 173-203. 1893. 

23. Olson, P. J., Bull, C. P., and Hayes, H. K. Ear type selection and yield in 

corn. Minn. Agr. Expt. Sta, Bui. 174. 1918. 

24. Shull, G, H, The composition of a field of maize. In Amer. Breeders' 

Assoc, Rpt. 4: 296-301. 1908, 

25. . A pure line method of corn breeding. In Amer. Breeders' Assoc. 

Rpt. 5: 51-59. 1909- 

26. Smith, L. H. Ten generations of corn breeding. 111. Agr. Expt. Sta. Bui. 

128, p. 486-488. 1908. 

27. Surface, Frank M. The result of selecting fluctuating variations. Data 

from the Illinois corn breeding experiments. Conference Internationale 
de Genetique, 4: 221-256. 1911. 

28. Waller, A. E. A method for determining the percentage of self-pollination 

in maize. In Jour. Amer. Soc. Agron., 9: 35-37. 1917. 

29. Williams, C. G., and Welton, F. A. Corn experiments. Ohio Agr. Expt. 

Sta. Bui. 282, p. 84-91. 191 5. ^ 



4 



BEAR & ROYSTON I NITROGEN LOSSES IN URINE. 



NITROGEN LOSSES IN URINE.^ 

Firman E. Bear and J. R. Royston. 
Introduction, 

Considerably more than half of the nitrogen of manure is contained 
in the urine. Thorne (6)^ gives the relative percentages of nitrogen 
in the dung and urine of dairy cows collected over a period of 24 
hours as 0.26 percent for the dung and 1.32 percent for the urine. 
Investigation has shown that where the urine is properly absorbed by 
litter and kept well packed under cover only slight nitrogen losses 
occur. On the modern dairy farm, however, the urine is collected in 
tanks without any absorbing material. As the urine usually stands 
in these tanks over a period of several months before being sprinkled 
upon the fields, the question naturally arises as to the loss of nitrogen 
in this method of preserving the urine. 

Nitrogen losses in urine by fermentation are due to the change of 
the urea and other nitrogen compounds to gaseous forms. The prin- 
cipal compound formed is ammonium carbonate, which easily breaks 
down to form ammonia, carbon dioxide, and water. When fresh 
urine comes in contact with putrid urine, as in the case of storage 
tanks, fermentation takes place rapidly, due to the organisms with 
which the putrid urine is charged. 

Storer (5) states that, with cow urine kept in tightly covered tanks, 
a loss in nitrogen of about 2 percent per month was observed. Vogel 
(7) observed that urine protected by an oil covering showed no ap- 
preciable loss of nitrogen. Without the oil covering and with long' 
exposure the nitrogen losses were very marked. 

In the investigations of Kristensen and Hansen (3) the manner of 
covering liquid manure tanks was found to be of great importance. 
Cow urine, kept in carefully covered tanks, contained on the average 
0.615 percent of nitrogen, while that from poorly covered tanks con- 
tained only 0.285 percent. The maximum amount of nitrogen in 
samples from carefully covered tanks was 0.836 percent and the mini- 
mum from poorly covered tanks was 0.169 percent. These results 

1 Contribution from the Department of Agricultural Chemistry and Soils, 
Ohio State University, Columbus, Ohio. Received for publication June 30, 1919. 

2 Reference is to " Literature cited," p. 326. 



320 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

were obtained from examination of the liquid manure on a number 
of Danish farms. Further experiments were conducted by Kristen- 
sen (4) on the storage of Hquid manure in a cistern 9.5 feet deep and 
17 feet wide for a period of 8 months. It was found that the nitro- 
gen content of the Hquid during this period decreased from 0.447 
percent to 0.350 percent, a loss of 21.7 percent. This loss is explained 
by the fact that there was an opening 3 inches wide and 6 inches long 
in the cover of the cistern thru which the pump projected. 

Laboratory experiments conducted by Deherain (i) for the pur- 
pose of explaining the losses of nitrogen from manure resulted briefly 
as follows : A solution of ammonium carbonate lost 73 percent of its 
nitrogen when exposed to the air for 30 days. In a closed flask, in 
which was -suspended a dilute solution of sulfuric acid to absorb the 
ammonia, the ammonium carbonate lost 12. i percent of its nitrogen 
in 3 days and 24.2 percent in 8 days. In closed flasks, provided with 
sulfuric acid to absorb the ammonia and sodium hydroxide to absorb 
the carbon dioxide, 39.3 percent of the nitrogen escaped in 3 days and 
83 percent in 8 days. 

Urine was then substituted for the ammonium carbonate solution 
and similar experiments conducted with it. When exposed to the 
air for a period of one month the urine lost 45 percent of its nitrogen. 
In a closed flask the loss in the same time was only from 5.6 to 6.6 
percent. In flasks provided with sulfuric acid to absorb the am- 
monia, 21 percent of the nitrogen escaped in 5 days, but at the end 
of that time none of the ammonia formed had been absorbed by the 
sulfuric acid. At the end of 11 days, however, 19 percent of the 
nitrogen of the urine was found in the sulfuric acid. When pro- 
vision was made for the absorption of both the ammonia and carbon 
dioxide in a closed flask there was a loss of only 2.9 percent of the 
nitrogen in 5 days, but of 52 percent in 11 days. 

In experiments in which litter was used to absorb the urine (i part 
litter to 2 parts urine) the loss of nitrogen in the open air during the 
summer was 7.2 percent in 8 days. In closed flasks in which arrange- 
ments were made for the absorption of the ammonia and carbon 
dioxide, 7.9 percent of the nitrogen escaped in 3 days, 31.5 percent 
in 6 days, 52.6 percent in 8 days and 59.7 percent in 12 days. In an 
atmosphere of carbon dioxide no nitrogen escaped from the mixture, 
altho the larger part of the nitrogen was converted into ammonia. 
The author concludes that this is the condition in a well-constructed 
and well-compacted manure heap. 



BEAR & ROYSTON : NITROGEN LOSSES IN URINE. 



321 



OBJECT OF THESE INVESTIGATIONS. 

It would appear from the above that a considerable amount of 
work has been done to determine the losses of nitrogen from urine. 
However, it seemed desirable to repeat and supplement some of the 
above work under controlled conditions in order that we might have 
a somewhat more definite conception of what this loss is under stor- 
age conditions such as obtain in America. 

PLAN OF THE EXPERIMENT. 

About 5 gallons of fresh urine were collected from the University 
herd of dairy cows early one morning when the cows first arose on 
being fed. Particles of dung were placed on muslin and the urine 
poured over them, thus inoculating the liquid with the intestinal flora. 
The urine was immediately removed to the laboratory. 

The method of procedure was planned with two general objects in 
view, viz: (i) to determine the losses of nitrogen from samples of 
urine exposed to the air in open beakers for varying periods of time 
at temperatures approximating winter and summer; and (2) to deter- 
mine the losses of nitrogen in samples of urine confined in flasks 
under the same temperatures with no evaporation permitted to take 
place. Accordingly, two series of trials were conducted. 

In Series I, duplicate 400-c.c. portions of urine were placed in 600- 
c.c. beakers and exposed to the air for periods of i, 2, 4, 8, and 12 
weeks, respectively. Duplicate samples representing each period of 
time were exposed in both the basement and attic of the building. 
The average temperature over the 12-week period from January 18 
to April 12 was 32.5° C. for the basement and 38° C. for the attic. 
These temperatures were taken daily at noon and variations were 
recorded by means of the thermograph. 

Included in Series I were three duplicate samples of 400 c.c. of 
urine covered with half-inch layers of kerosene. These were ex- 
posed at 32.5° C. for periods of 1,4, and 8 weeks. Also, two portions 
in duplicate of 20 c.c. of urine were placed in 600-c.c. beakers, ab- 
sorbed with filter paper, and exposed to the air for a period of 8 
weeks. One sample in duplicate was allowed to evaporate to dryness 
while the other was kept constant in weight by the addition of water 
from day to day. Blank beakers containing 400-c.c. portions of 
water were used to absorb any free ammonia in the air. 

In Series II, duplicate 200-c.c. portions of urine were placed in 500- 
c.c. graduated flasks equipped with Bunsen valves. These flasks 
were subjected to the same temperatures for the same periods of time 
as Series I. 



322 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



In addition to the flasks equipped with Bunsen valves three sets of 
duplicate samples were placed in tightly stoppered flasks and allowed 
to stand for periods of i, 4, and 8 weeks, respectively. Likewise, 
three sets of duplicate samples were placed in tightly stoppered flasks 
in which the air had been replaced by an atmosphere of carbon diox- 
ide. These also were allowed to stand for periods of i, 4, and 8 
weeks, respectively. 

As the different periods of time expired in each series, the nitrogen 
in the samples was fixed by the addition of sulfuric acid and the 
volume was made to 500 c.c. with water. At the end of the 12-week 
period aliquots containing i c.c. of urine were analyzed for total 
nitrogen by the Kjeldahl-Gunning method. 



LOSSES OF NITROGEN FROM URINE IN OPEN FLASKS. 

It will" be observed in Table i that there was a continual loss of 
nitrogen from the urine exposed to the air at 38° C. all thru a period 
of 8 weeks. The most rapid loss took place during the third and 
fourth weeks. At the end of 8 weeks the maximum losses under 
the conditions which obtained had evidently occurred. Those sam- 
ples allowed to stand for a period of 8 weeks evaporated to about 
half their original volume of 400 c.c, while those which stood for 
the 12-week period were reduced to about 80 c.c. 

Table i. — Nitrogen losses from urine exposed to the air at average tempera- 
tures of 38° and 32.5° C. 



Average temperature of 38° C. 



Time 
exposed. 



Nitrogen. 



Loss. 



Average temperature of 32.5° C. 



Sample 
No. 



Time 
exposed. 



Nitrogen. 



Weeks. 
Fresh 

I 

I 

2 

2 

4 

4 



Percent. 
63 
46 
46 
07 
09 
• 58 
.57 
.13 
•13 
.12 

.13 
o. 
o. 



Percent. 



10.42 
10.42 
34-35 
33-12 
64.41 
65-03 
92.03 
91.71 
92.63 
92-03 



13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23" 

24^" 



Weeks. 



Percent. 



Lost 
1.60 

I-5I 
1.48 
1.29 
1.29 

• 50 
•50 
.14 

• 13 
o. 

o. 



Samples ii, 12, 23, and 24 were water blanks to determine the amount of 
ammonia absorbed from the air. 



BEAR & ROYSTON: NITROGEN LOSSES IN URINE. 323 

With a temperature of 32.5° C. the most rapid loss took place be- 
tween the fourth and eighth weeks. For the entire 12-week period, 
however, the nitrogen losses approached the apparent maximum limit 
of about 92 percent. The loss in volume by evaporation at the lower 
temperatures was somewhat less than that of samples subjected to 
38° C. Samples exposed for 8 weeks evaporated to about two-thirds 
their original volume of 400 c.c, while those which remained for 12 
weeks were reduced to about 170 c.c. each. 

The oil-covered samples (Table 2) retained their original volumes 
thruout the period of the experiment with no appreciable evaporation 
of the kerosene. The loss of only 6.13 percent of total nitrogen for 
a period of 8 weeks as shown in Table 3 demonstrates the effective- 
ness of this simple method in conserving the nitrogen of the urine. 
It is probable that some of this loss occurred during the process of 
separating the oil from the urine, this being necessary before the 
sulfuric acid could be added to fix the nitrogen. 



Table 2. — Nitrogen losses from urine protected by oil or absorbed in paper 
when kept at an average temperature of 32.5'^ C. 



Protected by oil. 


Absorbed in paper. 


Sample 


Time ex- 


Nitrogen. 


Loss. 


Sample 


Time ex- 


Nitrogen. 


Loss. 


No. 


posed. 


No. 


posed. 




Weeks. 


Percent. 


Percent. 




Weeks. 


Percent. 


Percent. 


25 


I 


1-59 


2.45 


31" 


8 


1.38 


15-33 


26 


I 


1.59 


2.45 


32" 


8 


1.22 


25-15 


27 


4 


1.57 


3-68 


33^ 


8 


•05 


96.93 


28 


4 


lost 




34^ 


8 


.04 


97-54 


29 


8 


1.53 


6.13 










30 


8 


1.53 


6.13 











o Samples allowed to evaporate to dryness. 

^ Samples kept constant in weight by the addition of water daily. 



That phase of the experiment wherein urine was absorbed in filter 
paper was designed with the idea of obtaining data concerning the 
losses of nitrogen when the urine is absorbed by litter and exposed to 
the air. Pieces of filter paper were spread upon the bottom of the 
beaker in a flat, compact fashion until all the urine was absorbed. 
Samples 31 and 32 lost their moisture by evaporation within the first 
week, at the rate of approximately 3.5 grams daily. At the end of 
the 8-week period they were air dry and had lost 18.0 and 18.1 grams 
in weight, respectively. Samples 33 and 34, kept constant in weight 
by the addition of water daily, soon lost the characteristic odor of 
urine. The dry samples, on the other hand, retained this odor thru- 
out the period. 



324 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



It will be seen that the samples kept in a moist condition by the 
addition of water lost practically all of their nitrogen, 97.23 percent. 
From this it would seem that manure lying exposed to rain and sun- 
shine would be subject to great losses of nitrogen from fermentation 
and evaporation. In the dry samples, fermentation was probably 
checked by the lack of moisture, unfavorable conditions for bacterial 
action resulting. The loss in this case amounted to only 20.34 
percent. 

LOSSES OF NITROGEN FROM URINE CONFINED IN FLASKS. 

The object of this part of the experiment was to control the factor 
of evaporation without interfering with the normal bacterial activi- 
ties taking place in the urine. Accordingly, flasks were fitted with 
Bunsen valves to allow the escape of gases from within without per- 
mitting the access of air. Table 3 shows the results obtained. 

Table 3. — Nitrogen losses in urine in Bunsen valve flasks at temperatures of 

38° and 32.5" C. 



Average temperature of 38° C. 



Average temperature of 32.5° C. 



Sample 
No. 


Time 
exposed. 


Nitrogen. 


Loss. 


Sample 
No. 


Time 
exposed. 


Nitrogen. 


Loss. 




Weeks. 


Percent. 


Percent. 




Weeks. 


Percent. 


Percent. 


j-a 


I 


1.56 


3.98 


II 


I 


1.62 


0.61 


2 


I 


1.62 


.61 


12 


I 


1.63 


none 


3 


2 


1.62 


.61 


13 


2 


1.63 


do. 


4 


2 


1.62 


.61 


14 


2 


1.61 


1.22 


5 


4 


1.65 


1.22^ 


15 


4 


1.63 


none 


6 


4 


1-59 


2.45 


16 


4 


1.62 


.61 


7 


8 


1.64 


.61^ 


17 


8 


1.62 


.61 


8 


8 


1.63 


none 


18 


8 


1.62 


.61 


9 


12 


1.63 


do. 


19 


12 


1.63 


none 


10 


12 


1.62 


.61 


20 


12 


1.61 


1.22 



Loss by foaming on addition of H2SO4. 
6 Gain. 



A consideration of the analyses in Table 3 will show that the losses 
of nitrogen from the urine confined in the Bunsen valve flasks are so 
small as to be easily within the limits of experimental error. In sev- 
eral samples large white crystals were observed. When treated with 
concentrated sulfuric acid they readily dissolved with effervescence. 
This would indicate a carbonate, probably (NH4) C03. 

Table 4 further substantiates the conclusion drawn from Table 3 
that nitrogen losses occur only under aerobic conditions. A part of 
the samples were kept in tightly stoppered flasks thruout the various 



BEAR & ROYSTON I NITROGEN LOSSES IN URINE. 



periods of time, while in others the air was displaced by an atmos- 
phere of carbon dioxide. When the stoppers were withdrawn from 
the latter flasks a partial vacuum was observed in each flask. These 
samples also showed quite noticeable odor in contrast with the other 
samples. The color of the urine in these flasks was similar to that 
of the original. 



Table 4. — Nitrogen losses in urine in closed untreated flasks and in closed flasks 
in which the air was displaced by carbon dioxide, the average tempera- 
ture in each case being 32.5° C. 



Closed flasks with air. 



Closed flasks with carbon dioxide. 



Sample 
No. 


Time 
exposed. 


Nitrogen. 


Loss. 


Sample 
No. 


Time 
exposed. 


Nitrogen. 


Loss. 




Weeks. 


Percent. 


Percent. 




Weeks. 


Percent. 


Percent. 


21 


I 


1.61 


1.22 


27 


I 


1.63 


none 


22 


I 


1.62 


.61 


28 


I 


1.63 


do. 


23 


4 


1.63 


none 


29 


4 


1.63 


do. 


24 


4 


1.63 


do. 


30 


4 


1.63 


do. 


25 


8 


1.63 


do. 


31 


8 


1.61 


1.22 


26 


8 


1.63 


do. 


32 


8 


1.63 


none 



Summary. 

An inquiry into the losses of nitrogen from the urine of farm ani- 
mals was thought desirable because many farmers practice storing 
the liquid manure in tanks until convenient to apply it to the land. 
The question of the efficiency of these tanks in preserving the urine 
has often arisen. In these investigations a study was made as to 
nitrogen losses from urine (a) exposed to the open air, (&) in Bunsen 
valve flasks, {c) in closed flasks, {d) in closed flasks with the air dis- 
placed with carbon dioxide, {e) absorbed in litter, and (/) protected 
by layers of kerosene. 

It was observed that urine exposed to the air lost over 92 percent 
of its nitrogen over a period of 8 weeks under temperatures averaging 
38° C. Under temperatures averaging 5° less, approximately the 
same losses occurred over a period of 12 weeks. For shorter periods 
of time the losses were somewhat smaller at the lower temperatures. 

With urine not exposed to the air practically no losses took place 
under the various conditions of temperature, time, and methods of 
control. 

The effectiveness in preventing nitrogen losses by absorption of the 
urine in litter (filter paper) depended upon the method of handling 
the litter. Litter which was allowed to dry out and remain dry lost 
approximately 20 percent of its nitrogen content. On the other hand, 



326 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

litter kept in a moist condition by the daily addition of water lost over 
97 percent of its nitrogen, the greatest loss which occurred in any of 
the samples. 

Kerosene proved a fairly satisfactory means of preventing nitrogen 
losses. The samples of urine so protected lost approximately 6 per- 
cent of their nitrogen content over a period of 8 weeks. 

Literature Cited. 

1. Deherain, p. p. On the losses of ammonia which take place in the prepara- 

tion of barnyard manure. In Compt. Rend. Acad. Sci. [Paris], 19: 
1305-1310. 1898. 

2. Hawk, P. B. Digestion of urine in the determination of nitrogen by the 

Kjeldahl method. In Jour. Amer. Chem. Soc, 29: 1634-1637. 1907. 

3. Kristensen, R. K. Experiments with liquid manure as to loss of nitrogen 

during storage. In Tidsskr. Landbr. Planteavl, 14: 276-291. 1907. 

4. , and Hansen, F. Examination of barnyard manure and liquid manure 

on Danish farms. In Tidsskr. Landbr. Planteavl, 14. 515-570. 1907. 
Abs. in Expt. Sta. Rec. 20: 318. 1908. 

5. Storer, F. H. Chemistry of Agriculture, 2: 286. Charles Scribner's Sons, 

New York, 1906. 

6. Thorne, C. E. Farm Manure, p. 87. Orange Judd Co., New York City, 

1914. 

7. VoGEL, J, Experiments with liquid manure. In Mitt. Deut. Landw. Gesell., 

30: 498-502. 1915. Abs. in Chem. Abs., 10: 2509-2610. 



4 



HARTWELL I MANURIAL VALUE OF ORTHOCLASE. 



THE MANURIAL VALUE OF A MODIFICATION OF ORTHO- 
CLASE-BEARING ROCK WHERE ONLY POTASSIUM 
WAS DEFICIENT.^ 

Burt L. Hartwell. 

In July, 1912, the Institute of Industrial Research, Washington, 
D. C, after being in touch for a number of months with operations 
conducted on a mill scale by the Cushman-Coggeshall process, which 
had involved nearly 400 tons of raw material, stated that the treat- 
ment of feldspathic rock had been made economically and commer- 
cially possible ; but that it was desired to have agricultural tests con- 
ducted before proceeding much further with the development of the 
technical and commercial possibilities involved in the production of 
the form of " rock potash fertilizer " under consideration. The pur- 
pose of this paper is to report the results of an inextensive field trial 
conducted with this material at the Rhode Island station- during six 
years, now that this test has been terminated. 

The following information concerning the manufacture of the 
material has been furnished by the Institute of Industrial Research. 
The proper proportion of lime and feldspathic rock was ground 
together, and as the mixture was conveyed over a moving drum, a 
strong solution of calcium chlorid was sprinkled over it. This en- 
abled the formation of the material into clumps, from which the fine 
particles were sifted for subsequent treatment. The clumped ma- 
terial, about the size of peas, travelled continuously thru the rotary 
kiln where it was subjected to special heat treatment, after which it 
was rough ground in preparation for use. The finished product was 
said to consist mainly of silicates of aluminum, free lime, and potas- 
sium chlorid, a typical analysis being given as follows : Water-soluble 
potassium oxid, 4.3 percent; total potassium oxid, 5.7 percent; total 
calcium oxid, 16.0 percent. 

The orthoclase feldspar which was used was quarried principally 
in Maryland and contained about 10 percent of potassium oxid. 
Arguments which have been advanced against the commercial adop- 
tion of the method were that it would be impossible to get feldspar 

1 Contribution 261 from the Agricultural Experiment Station of the Rhode 
Island State College, Kingston, R. I. Received for publication August 12, 1919. 



328 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

that could be depended upon to run more than 8 percent potassium 
oxid and that the percentage in the mixture including the lime and 
calcium chlorid was so low that very little opportunity was left for 
incorporating sources of nitrogen and phosphorus so that a complete 
fertilizer might be produced. 

Six twelfth-acre plats of Warwick sandy loam soil were used for 
the experiment. All were kept supplied with equal optimum amounts 
of nitrogen, phosphorus, and lime. One of the plats did not receive 
any of the potassium, and one received a liberal amount, probably 
beyond the needs of the crops. The other four plats were given only 
a small amount of potassium, which was expected to be less eventually 
than the optimum requirements. These enabled a duplicated com- 
parison to be made between the effect of a high-grade commercial 
potash salt, sulfate or muriate, and of the rock potash fertilizer when 
furnishing the same amount of water-soluble potassium. 

In the spring of 191 3, several months after the rock potash fer- 
tilizer was received, it was found to contain 3.87 percent of potassium 
oxid soluble in water by the method of the Association of Official 
Agricultural Chemists. This determination was used as the basis 
of comparison thruout the experiment. 

To prevent the lime in the rock potash fertilizer from exerting any 
effect, in order that the value of the latter as a source of potassium 
only might be determined, i ton of ground limestone was applied per 
acre in 1913, and i ton of slaked lime together with 1,700 pounds of 
ground limestone in 191 5. 

In 1 91 3, the maximum application of potassium oxid was 60 
pounds per acre, and the smaller amount was 20 pounds; but the 
check plat without any potassium yielded fully as much corn, about 
35 bushels, as where it was applied. 

In 1914, the potassium applications of the previous year were re- 
peated and a crop of soybeans was grown for green manure, as the 
gravelly soil was quite poor in organic matter ; this crop was followed 
by rye as a cover crop. 

In 191 5, the suboptimum application of potassium oxid was in- 
creased to 30 pounds per acre, and the maximum to 90 pounds. 
Early potatoes were grown and it became evident during their de- 
velopment that there was finally a deficiency of potassium except 
where the maximum amount was applied. The bushels of potatoes 
produced per acre were 86 on the check plat, an average of 122 on 
the plats receiving muriate of potash, an average of 130 on the plats 
receiving, in the rock potash fertilizer, the same amount of soluble 



iiartwell: manurial value of ortiioclase. 



329 



potassium, and 206 on the plat receiving three times that amount or 
about 2,300 pounds per acre. Rape, soybeans, millet, and barley were 
grown after the early potatoes for turning in as green manure, and 
rye planted as a cover crop. 

In 191 6, the suboptimum and maximum applications of potassium 
oxid were increased to 50 and 100 pounds per acre respectively. 
White beans were grown but the yields were so inferior that they 
had no significance from the standpoint of the experiment. Rye 
was again sown as a winter cover crop. 

In 191 7, the potassium applications of the previous year were re- 
peated and early potatoes planted. The yields per acre were 233 
bushels on the check plat, 261 with sulfate of potash, 285 with the 
rock potash fertilizer supplying the same amount of soluble potas- 
sium, and 302 when twice the amount was added. 

After the removal of the potatoes, alfalfa was sown broadcast. In 
the spring of 1918, the same amounts of potassium oxid, 50 and 100 
pounds, were applied. Two crops of alfalfa hay amounted, in tons 
per acre, to 2.40 where there was no application of potassium, 2.57 
where sulfate of potash was added, 2.76 with the same amount of 
soluble potassium added in rock fertilizer, and 3.15 where twice as 
much was added. 

The efficiency of the two sources of potassium may be seen plainly 
by assembling the acre yields as shown in Table i. 

Table i. — Yields of potatoes and alfalfa obtained from the use of various 

potash fertilisers. 



Fertilizer applied. 



potatoes. 



1917. 
potatoes. 



1918, 
alfalfa. 



Check 

Suboptimum potassium: 

in muriate or sulfate of potash 
in rock potash fertiHzer 

Optimum potassium 



Bushels 
86 

122 
130 
206 



Bushels 
233 

262 
285 
302 



Tons 
2.40 

2.57 
2.76 
3.15 



The foregoing shows that under nutrient conditions which were 
believed to be suboptimum for only potassium, the rock potash 
fertilizer was slightly more efficient than high-grade muriate or 
sulfate of potash when supplying the same amount of water-soluble 
potassium. 



330 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



AGRONOMIC AFFAIRS. 
MEMBERSHIP CHANGES. 

The membership of the Society reported in the October number 
was 541. Since that time 8 new members have been added and i who 
was Hsted as resigned in a previous issue has rejoined the Society, so 
that the present membership is 550. The names and addresses of the 
new members and of the member who has rejoined, together with 
such changes of address as have been reported, follow. 

New Members. 

Ayers, W. E., 531 E. Jones St., Sherman, Texas. 

Cobb, J. Stanley, Agronomy Dept., State College, Pa. 

Donald, Lewis R., Agronomy Dept., State College, Pa. 

Feilitzen, Phil Hjvon, Moor Experiment Station, Jonkoping, Sweden. 

HiNDE, R. R., 211 N. Juliet Ave., Manhattan, Kans. 

Lewis, R. D., Agronomy Dept., State College, Pa. 

Potts, H. W., Agricultural College, Richmond, New South Wales. 

Wilkinson, Walter, University Farm, Davis, Cal. 

Member Reinstated. 
Call, L. E., Dept. of Agronomy, Kansas State Agr. College, Manhattan, Kans. 

Changes of Address. 

Bull, C. P., Worthington, Minn. 

Chapman, James E., 2316 Pierce Ave., St. Paul, Minn. 

Clark, Chas. F., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Cormany, Chas. E., 109 Catherine St., Ithaca, N. Y. 

GiLLis, M. C, 208 Delaware Ave., Ithaca, N. Y. 

Hagy, F. S., Kenton, Ohio. 

Haseltine, L. E., Hotel Shattuck, Berkeley, Cal. 
RuNK, C. R., Tippecanoe City, Ohio. 

TiNSLEY, J. D., 606 Union Station Bldg., Galveston, Texas. 

Viola, N, E., Hohentwil, Hombrechtikon, Switzerland. 

Wheeler, Clark S., 103 W. Miami Blvd., Dayton, Ohio. 

WiLKiNS, F. S., Dept. of Agronomy, College of Agriculture, Corvallis, Ore. 

Winters, N. E., 1414 E. Fourth St., Charlotte, N. C. 



AGRONOMIC AFFAIRS 



NOTES AND NEWS. 

C. P. Bull, formerly agronomist in charge of cooperative experi- 
ments at the ]\Iinnesota station, is now with the Humiston-St. John 
Seed Co. at Worthington, ]\Iinn. 

G. I. Christie, director of agricultural extension in Indiana, is 
superintendent of the International Grain and Hay Show which will 
be held in Chicago in connection with the International Livestock Ex- 
position, November 29 to December 8. 

A. H. Cockayne, biologist of the New Zealand Department of 
Agriculture, is spending several months in the United States, where 
he is studying agricultural methods and organization. 

J. A. Drake, who has been connected with the Federal Office of 
Farm Management since 1906, is now agricultural editor of Farm, 
Stock and Home. 

H. B. Fuller, of the Office of Extension Work in the North and 
West, States Relations Service, is now county agent leader in North 
Dakota, succeeding R. C. Pollock, who will do extension work for the 
Holstein-Friesian Association. 

Paul Emerson, formerly associate bacteriologist of the Idaho sta- 
tion, is now assistant professor of soils and assistant chief in soil 
bacteriology at the Iowa State College. At the same institution, H. W. 
Johnson has been promoted from assistant in soil bacteriology to asso- 
ciate professor of soils and assistant chief in soil chemistry in humus 
investigations. 

J. C. Hackleman, formerly extension agronomist in Missouri, is 
now extension agronomist in Illinois. 

Cyril G. Hopkins, chief of agronomy and agricultural chemistry in 
the University of Illinois since 1900, died at Gibraltar, October 6, 
while on his return journey from Greece, where he has been engaged 
for the past year in a study of the worn soils of that country for the 
American Red Cross. Doctor Hopkins was born in Minnesota in 
1866, graduated from the South Dakota Agricultural College in 1890, 
received his master's and doctor's degrees from Cornell University, 
and pursued advanced studies in agricultural chemistry at Gottingen 
in 1899 and 1900. He was a prolific writer on soil-fertility subjects, 
being the author of several books as well as numerous bulletins and 
articles in the farm press. Shortly before leaving Greece, he was 
decorated by the king for distinguished service. His death was due to 
congestion of the brain, with malarial complications. 



332 JOURNAL OF THE AMERICAN SOCIETY OF AGl* 



DeForest Hungerford, formerly assistant agronon .an- ^ 

sas station, is now farm management specialist with me lon de- 

partment in Georgia. 

L. S. Klinck, for the past several years dean of the co lege of agri- 
culture of the University of British Columbia, is now president of 
that institution. 

C. W. Mullen, assistant professor of farm crops at the Kansas 
college, resigned November i to become associate editor of the Okla- 
homa Stockman and Farmer, and has been succeeded by J. W. Zahn- 
ley, formerly of the department of education in the same institution. 

J. C. Russell, formerly assistant in chemistry at Nebraska Wesleyan 
University, is now assistant professor of soils at the University of 
Nebraska. 

B. F. Sheehan, formerly assistant professor of farm crops in the 
Oregon college, is now extension agronomist and state seed commis- 
sioner in Idaho, with headquarters in Boise. He has been succeeded 
in Oregon by F. S. Wilkins, formerly of the Iowa college. 

R. S. Snyder, formerly assistant in soil chemistry at the Iowa col- 
lege and station, is now assistant chemist of the Idaho station. 

Geo. F. Stuntz is now assistant agronomist of the Maryland station, 
succeeding W. J. Aitcheson. 

R. O. Westley, formerly assistant professor of agronomy in the 
Northwest School of Agriculture at Crookston, Minn., is now in- 
structor in farm crops in the Washington college. 

Clark S. Wheeler, director of the agricultural college extension 
service of Ohio State University, resigned November i to become 
assistant to the sales manager of the Domestic Manufacturing Com- 
pany of Dayton, Ohio. 

Under the new plan inaugurated July i in the college of agriculture 
of the University of California, by which the dean of the college is 
to nominate annually a director of resident instruction, a director of 
the experiment station, and a director of extension, Walter Mulford 
has been named as director of resident instruction for the current 
year, H. J. Webber director of the experiment station, and B. H. 
Crocheron director of agricultural extension. J. T. Barrett, professor 
of plant pathology, is acting director of the Citrus substation and 
acting dean of the Graduate School of Tropical Agriculture at River- 
side in the absence of Doctor Webber. 



JOURNAL 

; OF THE 

American Society of Agronomy 



Vol. II. December, 19 19. No. 9 



TAXING THE AIR FOR INCREASED FOOD PRODUCTION.^ 

J. G. LiPMAN. 

Wherever plant food is a limiting factor in crop production, acre 
yields are affected by the cost of commercial fertilizer as well as by 
the cost of land and labor and the market value of the crop. Cheap 
land and a limited supply of labor have, in the past, served to increase 
the size of the farm rather than the acre yield. In recent years, how- 
ever, certain changes have come into our economic life, and these 
changes will compel, if they are not already compelling, a substantial 
readjustment in our methods of soil treatment. 

As measured by European standards our land values may not be 
inflated, but they fluctuate now at levels much higher than those which 
prevailed in the memorable year of 1914. An acre of land that costs 
$300 cannot be neglected without financial discomfort to the owner 
or tenant. It must yield a return of $20 to meet fixed charges, and 
it must yield other returns to provide a living for the farmer. High- 
priced labor tends to become unprofitable under extensive and 
slovenly methods of production. On the other hand, the higher cost 
of plant food is more than offset by the increased value of farm 
products. The diversification in cropping now gaining momentum in 
certain of our agricultural districts, the increased acreage under crops 
of high commercial value, the manufacture of secondary agricultural 
prodticts, and the elimination of the middleman must all tend toward'^ 
more intensive methods of tillage and cropping. 

The readjustments just noted are forcing us to make a careful 
scrutiny of our plant food resources, to acquaint ourselves with the 

1 Presidential address before the twelfth annual meeting of the American 
Society of Agronomy, Chicago, 111., November lo, 1919. 

333 



334 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

supply and distribution of nitrogenous, phosphatic and potassic fer- 
tilizers. We are impelled particularly to take under observation the 
methods and practices of the Old World farmers who have been 
driven by the stress of our competition to constantly higher levels of 
production and who have survived in spite of our cheap and virgin 
fertility. We are impressed, as we study these Old World practices, 
by the skill with which nitrogenous manures are employed to supple- 
ment the nitrogen resources of the soil itself ; how in the use of these 
the farmers of Belgium, Germany and Great Britain have learned to 
attain the 30, 40, or even 50 bushel levels in the production of wheat, 
rye, and barley, to say nothing of the almost extraordinary yields of 
potatoes and beets. 

Without going too far afield, I shall try, with your permission, to 
discuss only a single phase of our fertilizer and fertility problem, 
namely, the more systematic and more intensive use of nitrogen com- 
pounds that are the resultants of electrochemical and microbiological 
processes. But before I attempt a discussion of the use of these com- 
pounds, I must establish certain premises which relate directly to 
the gains and losses of nitrogen from the arable land in the United 
States. Some of the data which I shall now place before you were 
gathered for another purpose, but will serve very well the purpose 
which I now have in mind. 

LOSSES OF SOIL NITROGEN. 

In his report for 1918, Secretary of Agriculture Houston estimates 
the area devoted to the more important staple crops at 289,073,300 
acres. This acreage does not include the cultivated forage crops like 
alfalfa, timothy, and clover. With these included, the area of arable 
land in the United States is well above 300,000,000 acres. Taking 
300,000,000 acres as a very conservative basis for estimating the gains 
and losses of nitrogen from arable land in the United States, we find 
the following: 

1. The loss of nitrogen from the average acre of arable land may 
be taken at 60 pounds per annum. This estimate is based on a care- 
ful study of available data in European and American literature. 
Hence, at 60 pounds per acre, the annual loss from 300,000,000 acres 
of arable land would correspond to 9,000,000 tons of nitrogen. 

2. The losses of soil nitrogen are, in part, offset by applications of 
animal manures, by the growing of leguminous crops, by atmospheric 
precipitation, by non-symbiotic nitrogen fixation in soils, and by the 
use of commercial fertilizers. 



LIPMAN : INCREASED FOOD PRODUCTION. 



335 



It is estimated by Secretary Houston that, in 191 8, there were on 
the farms in the United States approximately 26,000,000 horses 
and mules, 66.800,000 beef and dairy cattle, 48,900,000 sheep, and 
71,400,000 swine. The manure produced by these animals contains 
an equivalent of 5,250,000 tons of nitrogen. Had all of this nitrogen 
been available for restoring the loss of this constituent from our 
arable land, the balance sheet would be a more favorable one than it 
actually is. It has been clearly demonstrated by numerous studies in 
this country and abroad that, aside from the nitrogen retained in the 
bodies of domestic animals, extensive losses of this constituent are 
caused by leaching and by fermentations in manure. Account should 
also be taken of the nitrogen left on the ranges and pastures in the 
droppings of domestic animals. All told, not more than one third 
of the nitrogen calculated as present in the manure of domestic ani- 
mals is actually made available for crop uses. Hence, it may be 
assumed that the manure of the domestic animals in the United 
States annually restores to the arable land of this country an equiva- 
lent of 1,750,000,000 tons of nitrogen. 

It may be assumed further, that our 20,000,000 acres of timothv 
and clover would increase the nitrogen content of the soil by 50 
pounds per acre per annum; our 10,000,000 acres of alfalfa at the 
rate of 100 pounds of nitrogen per acre per annum ; our 5,000,000 
acres of velvet beans at the rate of 100 pounds of nitrogen per acre 
per annum; and our 10,000,000 of acres of miscellaneous legumes at 
the rate of 50 pounds of nitrogen per acre per annum. The total 
addition in these leguminous crops may be taken, therefore, as equiv- 
alent to 1,750,000 of tons of nitrogen. 

Atmospheric precipitation in the form of rain, snow, hail, and dew 
adds to the soil srriall quantities of combined nitrogen varying from 
2 to 3 to as much as 10 pounds per acre per annum. An allowance 
of 5 pounds of nitrogen per acre per annum would be well above the 
average for the 300,000,000 acres of arable land. The total would 
correspond to an equivalent of 750,000 tons of nitrogen. The amount 
of nitrogen fixed in the soil by Azotobacter and other non-symbiotic 
nitrogen-fixing organisms cannot be estimated with any degree of 
accuracy. For the 300,000,000 acres of arable land it may be equiva- 
lent to a minimum of 500,000 tons and a maximum of 1,500,000 tons 
of nitrogen. The additions in the form of commercial fertilizers 
would be equivalent to about 200,000 tons of nitrogen. 

It seems, therefore, that the nitrogen compounds added to our 
arable land in the form of animal manures, leguminous green manures 



336 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



and residues, the body substances of non-symbiotic nitrogen-fixing 
organisms, ammonia and nitric acid in atmospheric precipitation, and 
nitrate, ammonia, and organic nitrogen in commercial fertilizers rep- 
resent an equivalent of five to six millions of tons of nitrogen. This 
leaves a net deficit of possibly three to four millions of tons of nitrogen 
for the 300,000,000 acres of arable land. The net loss is equivalent, 
therefore, to fifteen to twenty millions tons of sulfate of ammonia. 

3. The losses of soil nitrogen are greatest in the regions of limited 
rainfall and of high summer temperatures, such as the northern 
Great Plains States. Under the conditions prevailing in this region, 
much of the nitrogen lost is due to the destructive decomposition of 
organic matter with the evolution of elementary nitrogen. Very in- 
tensive losses occur in the Southern States on account of the long 
open season, the relatively rapid oxidation of organic matter in the 
soil, and the leaching out of the nitrates formed. Very serious losses 
of soil nitrogen also take place in the Central States, largely on ac- 
count of the faulty rotations in vogue and the failure to maintain a 
suitable soil reaction for the growing of legumes. 

THE FIXATION OF AIR NITROGEN. 

Fertilizer nitrogen is at best only a supplement to nitrogen derived 
from the soil itself. Every effort should be made to utilize crop 
residues and green manures or other natural resources of nitrogen, 
in order to decrease, in so far as it may be practicable and profitable, 
the need for the purchase of nitrogen in mineral products. When 
that point is reached the sources of commercial nitrogen should be 
drawn upon to insure maximum returns under any given conditions. 

Among the more common and effective methods for increasing the 
supply of nitrogen in the soil may be included the provision for an 
increased acreage of legumes and such shortening of our crop rota- 
tions as would make legumes relatively more prominent. Of late 
years there has been a notable expansion in the acreage of velvet 
beans, soybeans, peanuts, alfalfa, and sweet clover. The acreage of 
these and other legumes should be increased still further. By such 
expansion we should make certain of increased additions of nitrogen 
running into the hundreds of thousands of tons. 

Recognizing the striking differences that exist in the ability of dif- 
ferent legumes to assimilate atmospheric nitrogen, we should make 
an effort to grow such legumes as would, without prejudice to the 
other interests of the farmer, show the greatest degree of efficiency in 
fixing atmospheric nitrogen. 



LIPMAN : INCREASED FOOD PRODUCTION. 



337 



By way of illustration, one could refer here to the more pronounced 
ability of soybeans as compared with cowpeas in assimilating air ni- 
trogen. Grown under the same conditions, the air-dry matter of soy-_ 
bean hay may contain 5 percent of nitrogen as compared with cowpea 
hay containing only 3 percent of nitrogen. These differences are 
inherent in the crops themselves, but there are lesser and yet im- 
portant differences within different strains and varieties of the same 
crop. Hence, a splendid opportunity exists for improving our culti- 
vated leguminous crops by selection and breeding, such improvement 
to lay stress on increasing the nitrogen-gathering power of the crops 
in question. 

The fixation of nitrogen by leguminous crops, as well as by Azoto- 
bacter and other bacteria active in the soil itself, bears a direct and 
important relation to the chemical and physical nature of the soil. 
The reaction of the latter, the nature of the soil solution, the circu- 
lation of air, the water supply, and the quality and quantity of the 
organic matter all affect the activities of soil microorganisms and 
determine the extent of nitrogen fixation. There is room for a 
more systematic study of our cultivated soils for the purpose of en- 
abling us to make these the most satisfactory culture media for 
nitrogen fixation. There is also room for improvement in the char- 
acter of the microorganisms on which we depend for the assimilation 
of air nitrogen. It has been known for a long time that bacteria 
derived from different soils show more or less marked differences in 
their ability to assimilate elementary nitrogen. It would be reason- 
able to assume that, by careful selection, types of nitrogen-fixing 
bacteria might be developed that would be decidedly more efficient 
than most of those present in our cultivated soils. 

As a supplement to the methods employed for increasing the fixa- 
tion of atmospheric nitrogen by microorganisms alone, or by micro- 
organisms acting in association with higher plants, the conservation 
of manure and soil nitrogen should receive very earnest considera- 
tion. The vast losses of soil nitrogen already referred to in this 
paper could be materially lessened by more adequately protecting our 
cultivated soils against leaching and surface washing. The enormous 
quantities of nitrates carried away in the surface drainage of the 
humid regions of the United States could, to a very substantial ex- 
tent, be retained for future use by a more systematic covering of the 
land when the main crops are not growing. There is hardly need to 
more than mention the inexcusable losses of soluble nitrogen com- 
pounds from the manure of our domestic animals. The losses which 



338 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

occur in farmyard manure on account of leaching, the escape into the 
air of ammonia and of free nitrogen, and the transformation of rela- 
tively available into unavailable nitrogen compounds through bac- 
terial action are, to a great extent, preventable. The more thoro 
conservation of this nitrogen would substantially decrease the need 
for the purchase of nitrogen in commercial fertilizers. 

After the so-called home resources of nitrogen are utilized to the 
fullest extent, there will still be ample opportunity for further and 
profitable increase in crop yields thru the use of manufactured nitro- 
genous fertilizers. Students of soil fertility in this country and 
abroad are generally agreed that, under more intensive methods of 
production, the increased use of nitrogenous fertilizers is a means 
for increasing profits in so far as plant food is at all a limiting factor 
in production. Of late years, there has been a remarkable expansion 
in the manufacture of so-called technically fixed nitrogen products. 
The stimulus of military necessity led to an amazing increase in the 
production of synthetic ammonia and of cyanamid in Germany. It 
is stated on good authority that the German plants have a capacity 
equivalent to 500,000 tons of fixed nitrogen per annum. The cyana- 
mid plants have a capacity of 300,000 tons, while those using the 
Haber process have a capacity of 200,000 tons per annum. Of 
course, the actual production falls very far short of the present 
capacity. The existing difficulties as to labor, transportation, and 
fuel supply may not permit the fixation of more than 100,000 tons of 
atmospheric nitrogen at the German plants during the year 1919. 
Nevertheless, even under present abnormal conditions, technically 
fixed nitrogen is playing an important role in meeting the needs of 
agricultural production. Within a very few years the world capacity 
for technically fixed nitrogen may be equivalent to 1,000,000 tons of 
nitrogen or 5,000,000 tons of sulfate of ammonia. There is almost 
no limit to the kinds of fixed nitrogen products which may be manu- 
factured for agricultural uses. Among the products already pro- 
duced on a large scale or in an experimental way may be mentioned 
nitrates, such as potassium, ammonium, and sodium nitrate ; am- 
monium salts, including sulfate, nitrate, chloride, phosphate, and 
bicarbonate ; double salts, as potassium ammonium nitrate and sodium 
ammonium nitrate ; and urea or derivatives like urea nitrate, urea cal- 
cium nitrate, urea superphosphate, etc. From the standpoint of 
quantity, cyanamid is, no doubt, the most important of the fixed 
nitrogen products. It has been successfully used as a fertilizer in 
Europe and in the United States. It has, however, certain limita- 



LIPMAN : INCREASED FOOD PRODUCTION. 



339 



tions which make it unpopular among the farmers, and it is rather 
generally agreed that its greatest value will lie in its serving as a 
source of secondary products rather than in supplying directly com- 
bined nitrogen for crop production. It is well known that cyanamid, 
when steamed under pressure, will readily give up its nitrogen as 
ammonia. The ammonia thus produced can be utilized for the 
making of different ammonium salts or for oxidation to nitric acid. 

Aside from cyanamid, large quantities of calcium nitrate and of 
ammonium nitrate are now being manufactured. The production of 
calcium nitrate is practically limited to Norway. In 1918, about 
61,000 tons of calcium nitrate were produced in that country. Nearly 
all of this was consumed in Norway for agricultural purposes ; only 
a small proportion was exported. There is adequate experimental 
evidence to show that calcium nitrate is a very satisfactory nitrogen- 
ous fertilizer. Unfortunately, however, it is distinctly hygroscopic 
and difficult to apply thru fertilizer distributors. A granulated cal- 
cium nitrate is now being made in Norway which, in part, overcomes 
this objection. The farmers of Norway seem to be able to use it 
with much satisfaction to themselves, but, on the whole, the material 
is too hygroscopic for extensive use in other countries. Ammonium 
nitrate is also a satisfactory source of nitrogen when considered from 
the crop standpoint. It is, however, hygroscopic and, for this reason, 
objectionable. Farmers are also afraid of it because of its tendency 
to catch fire under certain conditions of storage. When used in the 
row it is apt to cause a very concentrated soil solution, with unde- 
sirable efifects on germinating seed or young plants. In the case of 
cyanamid, interference with germination, more or less permanent 
injury to growing vegetation with which it is brought in contact, and 
injury to men and animals engaged in its distribution create serious 
objection to its extensive use in agriculture. The secondary products 
which will be developed from cyanamid, in order to be acceptable, 
will have to be free from the objections just noted. 

THE POSSIBLE USE OF NITROGEN FERTILIZERS. 

The more intensive use of nitrogenous fertilizers is essentially a 
problem in economics. It is obvious that, for crops of low commer- 
cial value, nitrogenous fertilizers, if used at all, can be used in limited 
amounts only. European as well as American experience seems to 
indicate that, with adequate rainfall and in the presence of adequate 
quantities of other plant-food constituents, supplemental applications 
of commercial nitrogen equivalent to 15 to 25 pounds per acre may 



340 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

be profitable. Employed for crops of high commercial value the 
corresponding applications would be much larger, viz., 50 to 75 
pounds per acre. A careful survey of the situation would show that 
for the 37,000,000 acres of cotton in the cotton belt nitrogenous fer- 
tilizers could be used effectively for supplementing the soil resources. 
A large part of the cottonseed meal now used as a source of nitrogen 
for the cotton crop should be replaced by nitrogen in mineral salts. 
This would not only lead to an increase in yield, but would also con- 
serve large quantities of cottonseed meal which should be employed 
in the feeding of live stock. Similarly, in the case of the 46,000,000 
acres of corn in the Southern States, at least 20,000,000 acres would 
respond to supplemental applications of nitrogen. In the Central 
States there are 6,000,000 acres of wheat, 20,000,000 acres of corn, 
10,000,000 acres of oats, and 10,000,000 of grass that will respond to 
nitrogen treatment. In the North Atlantic States there are 11,000,000 
acres of grass, 3,000,000 acres of corn, 2,000,000 acres of wheat, 
3,000,000 acres of oats, and 1,000,000 acres of potatoes that will 
similarly respond to applications of nitrogenous fertilizers. All tolG> 
the increasing cost of labor and the increasing values of cultivated 
land will compel more intensive methods of production and lead us 
to revise our fertilizer practices in order that the average acre, as 
well as the average farm worker, may be made more efficient in the 
production of human food. 

THE NEED OF RESEARCH AND DEMONSTRATION. 

The use of the technically manufactured nitrogenous fertilizers 
will be affected by soil, plant, and climatic conditions. The nature of 
the soil itself must determine the type of nitrogenous fertilizer which 
is likely to prove most advantageous. In certain soils ammonium 
salts are to be preferred, while in other soils nitrates would be by far 
the most satisfactory source of available nitrogen. The chemical 
and mechanical conditions of the soil, the content of organic matter, 
and its reaction must determine the amounts and kinds of nitrogenous 
fertilizers that would give the most profitable returns. Over a large 
section of the United States the soils are decidedly basic in character. 
This is particularly true of the arid and semiarid regions. Where 
danger exists of the accumulation of black alkali, sodium nitrate is a 
far less satisfactory source of nitrogen than ammonium salts. On 
the other hand, soils distinctly acid in character are much less suit- 
able for the use of ammonium salts than they are for the use of 
nitrates. It is also recognized that the ability of the soil to retain 



LIPMAN : INCREASED FOOD PRODUCTION. 



fertilizing materials or to lose these when the rainfall is large is a 
varying and important factor in establishing fertilizer practice. 

In the use of technically fixed nitrogenous fertilizers urea or other 
organic compounds may at times possess advantages that are not 
possessed by ammonium salts or nitrates. The farmers in the Old 
World have very decided preferences as to the source of nitrogen 
for their crops. Farmers on the continent of Europe and in Great 
Britain seem to feel that anniionium sulfate is much more satisfac- 
tory than sodium nitrate for the growing of potatoes. On the other 
hand, they feel that, for the growing of sugar beets and mangolds, 
sodium nitrate is to be preferred. They also recognize that, for early 
vegetables and for cereals and grasses that need stimulating early in 
the spring, nitrates are much more effective than ammonium salts. 
Farmers in the United States who have had experience in the use of 
nitrogenous fertilizers have often reached the same conclusion. It is 
hardly necessary to go into further detail concerning the points just 
noted.- There scarcely need be any difference of opinion as to the 
desirability of further fundamental research on the use of concen- 
trated nitrogen salts in American agriculture. A broad foundation 
must be established in which the factors of soil, climate, crop, and 
the nitrogenous fertilizers themselves would be assigned the proper 
place. Also from the economic standpoint there is need of careful 
study as bearing on types of farming, the cost of crop production, the 
value of the products and the skill and intelligence of the farmer. 
It will be found in the carrying on of such economic studies that the 
methods of application will prove to be a factor of considerable sig- 
nificance. 

Much valuable information has already been accumulated by Amer- 
ican investigators on the importance of our different nitrogenous 
manures and fertilizers for increasing production. The action of 
these manures and fertilizers is not always clearly understood be- 
cause of our failure to date to outline our studies on a broader foun- 
dation. The time is ripe for cooperation among soil investigators in 
the study of the entire problem as it relates to agricultural production 
in the United States and particularly as it relates to the use of tech- 
nically fixed nitrogen products, whose future use is not only certain 
to be very large but whose composition and cost will play a prominent 
role in determining production and cost of human food. 



342 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



THE WORDS PRODUCTIVITY, OR PRODUCTIVENESS, AND 
FERTILITY AS APPLIED TO AGRICULTURE.^ 

C. V. Piper. 

The word fertility (Latin fertilitas, from ferro, to bear) was orig- 
inally used by the Romans when applied to agriculture with the mean- 
ing of fruitfulness, that is, productiveness in large measure. The 
original application of the words fertile and fertility was primarily to 
regions or areas that produce abundant crops, for example, a fertile 
valley. 

The words productivity and productiveness come from the Latin 
prodiico, to lead forth or to bring forth. In Roman usage the verb 
was used with various different meanings, among them that of bring- 
ing forth young. Only after the Augustan age was the word used in 
reference to the raising of crops. Our English words productivity 
and productiveness had no exact equivalents that were in use by the 
Romans. 

The word productivity has retained in agriculture practically un- 
varied meanings. In a potential sense it signifies the quality or qual- 
ities of a region which enable it to grow useful crops, and in an actual 
sense productivity is the measure of the yields of a region as ex- 
pressed in such units as pounds, bushels, tons, etc. The agricultural 
productivity of any region is conditioned on four series of factors, 
the climate, the soil, the adapted crop plants, and the adequacy of cul- 
tivation. The highest productivity exists where all four of these con- 
ditions are associated. 

The word fertility in modern times has tended to become more and 
more restricted to the conception of soil fertihty, thus excluding the 
other potent factors that make for productivity. In the restriction of 
the word fertility to this idea of soil fertility, various theories as to 
the nature of soil fertility have been advanced consecutively, namely, 
(i) that it is due to humus or vegetable matter; (2) that it is mainly 
a matter of physical condition or tilth ; (3) that its basis is the amount 
and availability of certain chemical substances and especially com- 

1 Prepared as " Contribution to Agronomic Terminology — 5 " by the chair- 
man of the Committee on Agronomic Terminology, C. V, Piper, and read at 
the twelfth annual meeting of the American Society of Agronomy, Chicago, 
III, November 12, 1919, by C. R. Ball. 



piper: productiveness and fertility. 



343 



pounds of nitrogen, phosphorus, and potash ; and (4) that yields are 
restricted by the presence of injurious organisms or substances in the 
soil. So far as present evidence goes, there may be and probably is 
truth in all the theories, but no one of them alone can be accepted as 
fully explanatory of the phenomena. 

Nevertheless, many writers who accept the third theory have re- 
stricted the meaning of the phrase soil fertility and even of the word 
fertility to the three so-called plant nutrients, nitrogen, phosphorus, 
and potash, and attempt to measure the degree of fertility by the rela- 
tive amounts and solubility of these substances. Where the word fer- 
tility is used in this last sense its relation to productivity may be 
reduced to zero, as in very cold, very wet, or very dry regions. 
While there can be no doubt of the important relations of nitrogen, 
phosphorus, and potash in the soil to the growth of plants, it is gen- 
erally admitted that no method of soil analysis yet devised will enable 
one to determine relative productivity, at least for the great majority 
of soils. Potential productivity may be measured as actual productiv- 
ity in terms of pounds, bushels, or tons per acre. However, it will 
lead to absurdity if productivity in different regions is measured by 
the same crop or the same series of crops. The real measures of pro- 
ductivity are the useful crops of one kind or another that can be 
grown or are actually obtained in the region. To compare North 
Dakota and Georgia on the basis of either flax, or cotton production is 
manifestly absurd. 

In view of the fact that the word fertility is often used in agri- 
culture in the narrow sense of soil fertility or even of one of the 
theories of soil fertility, as well as in its broader original meaning, it 
is an unsatisfactory and often ambiguous terms to use in technical 
pubHcations. Productivity or productiveness, both in their potential 
and actual applications, are words whose clearness has not been im- 
paired by the evolution of ideas, and therefore they should be em- 
ployed in preference to the word fertility as used in its broad ap- 
plication. 

A further advantage of this proposal is not unimportant. As 
before stated, the word fertile means productive in a high degree. 
Therefore, it approaches the absurd to speak of low fertility, mod- 
erate fertility, etc. Fortunately the words productivity and produc- 
tiveness have in them no such meaning either actual or implied. It is 
therefore entirely proper to speak of low productivity, high produc- 
tivity, etc. 



344 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



AGRONOMIC AFFAIRS. 

REPORT OF THE SECRETARY-TREASURER. 

This report covers the period from January i, 1919, to October 31, 1919, 
inclusive. 

The decline in membership so noticeable in 1918 has extended in a some- 
what modified form into 1919. The resignations and lapses from the non- 
payment of dues are still excessive, but partly to counterbalance these losses 
there have been more subscriptions and new members added than last year. It 
begins to appear to the Secretary-Treasurer that the unusual conditions result- 
ing from the war and the high cost of living, which have adversely affected many 
scientific societies, are passing and that The American Society of Agronomy is 
back again on a stable basis. 

One matter which I wish especially to call to the attention of the membership 
is the favorable notice given to the Society in foreign countries. This is evi- 
denced by the continually increasing subscriptions to the Journal from foreign 
sources. Libraries of our own country, other than those of agricultural col- 
leges and experiment stations which have hitherto made up the larger part of 
our subscription list, are more and more coming to recognize the merit of the 
Society and are not only subscribing for the Journal, but are purchasing com- 
plete sets of the back numbers of the Proceedings and of the Journal. This 
is a condition which should make us all justly proud and should spur us on to 
give still better service. Investigators with material to present to the agronomic 
profession can. find no medium of communication where their papers will be 
more widely read at the present time and less likely to be buried from future 
investigators, than in the Journal of the American Society of Agronomy. 

The Society started the year with a paid-up membership of 509. Since then, 
52 new members have been added for 1919 and 2 for 1920, 16 have been rein- 
stated, I has died, 25 resigned, and 80 have let their membership lapse for non- 
payment of dues. This leaves the Society with a paid-up membership of 473. 
In addition to this membership, there are 105 subscribers to the Journal, some 
of them for two or more copies. 

A special effort was made to enlarge the membership by asking certain 
agronomists to solicit new members in their respective States. Several re- 
sponded with a number of candidates for admission. It has been my experience 
that a formal request' seldom gets a new member, but a personal appeal from 
a friend who is already a member is what is needed to increase our member- 
ship. In this connection I wish to commend the work of a number of agrono- 
mists who have helped much in the past in getting new members, especially W. 
C. Etheridge of Missouri, John H., Parker and L. A. Fitz of Kansas, L. H. 
Smith of Illinois, John R. Fain of Georgia, and J. F. Cox of Michigan. If all 
of the States were represented in the Society in proportion to their agronomic 
workers as are New York, Ohio, Georgia, Kansas, and Missouri, our member- 
ship would soon be considerably larger than it is now. 



AGRONOMIC AFFAIRS. 



345 



The Secretar3--Treasurer wishes to apologize for numerous dela3'S and some 
errors in conducting the business of the Society. Being employed in work which 
makes it necessar}- for him to be absent from his office for weeks and sometimes 
months at a time, such delays are unavoidable. The indulgence and good will 
evidenced by the members in spite of these shortcomings is highly appreciated. 

Financial Statement from January i, 1919, to October 31, 1919. 

Receipts. 

Balance on hand from previous year $ 565.00 

Dues from members: 





at $2.50 


$1 0'^2 ^0 


I member for 1919 


at 


.50'' 




I member for 1919 


at 


2.25^ 


2.25 


I member for 1919 


at 


I ^0^ 


1.50 


7 members for 1920 


at 


2 =;o 


17 ^0 




at 


1. 00'^ 


3 00 




at 


2.50 


15.00 




at 


.50 


1. 00 


51 new members for 1919 


at 


2.50 


127.50 


I new member for 1919 


at 


2.00^' 


2.00 


I new member for 1920 


at 


2.50 


2.50 


I new member for 1920 


at 


2.00'^ 


2.00 


7 local members (Washington, D. C, section) at 


.50 


3-50 


Journal and Proceedings: 








52 subscriptions for 1919 


at 


2.50 


130.00 


23 subscriptions for 1919 


at 


2.25& 


51.75 


5 subscriptions for 1918 


at 


2.50 


12.50 


I subscription for 1918 


at 


2.25^ 


2.25 


2 subscriptions for 1920 


. . at 


2.50 


5.00 




at 


2.25^ 


6.75 




at 


2.00 


2.00 








228.03 


Sale of reprints 






56.25 



Total receipts $2,270.28 

^ Balance paid in 1918. 

^ Agent's commission deducted. 

^ One dollar still due to the Society. 

^ Advance credits. 

^ Fifty cents still due to the Society. 

Note: There were 4 advance payments of dues for 1919 and dues of 2 new 
members for 1919 reported in 1918. Outstanding bills for Journal and Pro- 
ceedings amount to $18.45 and 18 subscriptions are in arrears for 1919. 

Disbursements. 



1919. 

Jan. 4. Telegram $ 0.64 

Jan. 7. Rent of lantern 10,00 

Jan. 13. Postage 40.00 



34^ JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Jan. 14. Postage 2.61 

Jan. 18. Refund on overpayment on Journal 1.35 

Feb. I. Maurice Joyce Engraving Co 18.57 

Feb. I. Lewis M. Thayer, printing 13.25 

Feb. 7. The Colonial Press, printing 4.15 

Feb. 15. Maurice Joyce Engraving Co 7.30 

Feb. 15. Lewis M. Thayer, printing 80.50 

Feb. 27. Postage 2.73 

Mar. 8. New Era Printing Co 161.69 

Mar. 8. Maurice Joyce Engraving Co 7.25 

Mar. 25. Postage 1.88 

Mar. 29. Maurice Joyce Engraving Co 30.07 

Apr. 23. Postage 1.55 

Apr. 25. Postage 2.09 

May 22. Postage 2.50 

May 15. Maurice Joyce Engraving Co 23.00 

June 16. Mary Burr, clerical services 22.00 

June 16. Mary Burr, postage, etc 5.00 

June 16. Postage 3.00 

July 22. Postage 5.00 

July 23. New Era Printing Co 583.73 

Sept. 8. New Era Printing Co 665.51 

Oct. 15. Postage 9.00 

Oct. 21. The Colonial Press 4.28 

Oct. 24. Maurice Joyce Engraving Co 10.03 

Oct. 30. Maurice Joyce Engraving Co 4.30 

Oct. 30. Mary Burr, clerical services 5.50 

Oct. 30. Telegram 1.05 

Total disbursements $1,742.26 

Balance on hand October 31, 1919 528.02 



$2,270.28 
Lyman Carrier, 
Secretary-Treasurer. 



MINUTES OF THE TWELFTH ANNUAL MEETING. 

Chicago, III., November lo-ii, 1919. 

First Session, Monday Afternoon, November 10. 

The meeting was called to order by President J. G. Lipman. The following 
papers were presented : 

1. Some Considerations of an Interspecific Cross of Medicago, by L. R. 
Waldron. 

2. The Effect of 23inc in Soil Tests with Galvanized Pots, by S. D. Conner. 

3. a. The Truefast Test for Sour Soils; b. Status of Lime in Soil Improve- 
ment, by Elmer O. Fippin. 



AGRONOMIC AFFAIRS. 



347 



4. Reduction of Nitrates Caused by Seed as a Possible Factor in Crop Pro- 
duction, by J. Davidson. 

5. Cereal Investigations During the War, by Carleton R, Ball. 

6. Federal Seed Grain Loans, by C. W. Warburton (read by title in the ab- 
sence of the author). 

Second Sessioii, Monday Evening, November 10. 
Mr. C. G. Williams, presiding. 

7. Taxing the Air for Nitrates, by Dr. J. G. Lipman, President of the Amer- 
ican Society of Agronomy. 

At the close of this meeting those interested in teaching soils held an in- 
formal discussion on that subject. 

Third Session, Tuesday Morning, November 11. 

8. Discussion : Teaching Farm Crops. Leaders, W. L. Burlison and E. G. 
Montgomery. 

9. Correlation Between Length of Mother Head and Yield of Progeny in 
Wheat, by A. N. Hume. 

10. Some Observations on the Behavior of Smooth and Bearded Wheat, by 
A. E. Grantham. 

Fourth Session, Tuesday Afternoon, November 11. 

11. The Coefficient of Yield, by F. S. Spragg. 

12. Discussion : Standardization of Agronomic Experiments. Leader, S. C. 
Salmon. 

Business Meeting. 

The report of the Secretary-Treasurer, as presented elsewhere in this issue, 
was read. 

The Auditing Committee reported as follows : 

Report of Auditing Committee. 

We have audited and found correct the statement of receipts and disburse- 
ments of Lyman Carrier, Secretary-Treasurer of The American Society of 
Agronomy. 

(Signed) L. E. Call, 

A. R. Whitson, 
Committee. 

By vote of the Society, the report of the Secretary-Treasurer was approved. 

The report of the Editor, as published elsewhere, was approved. 

In lieu of a report by the Committee on Terminology, a brief paper on 
" The Words Productivity, or Productiveness, and Fertility as Applied to Agri- 
culture," prepared by the chairman, C. V. Piper, was read by C. R. Ball. This 
paper is published elsewhere in this issue. 

The report of the Committee on Varietal Nomenclature was read by the 
chairman, E. G. Montgomery. This was approved on motion, and is printed 
elsewhere in this issue. 

The Nominating Committee, consisting of George Roberts, chairman, E. G. 



348 JOURNy\L OF THE AMERICAN SOCIETY OF AGRONOMY. 



Montgomery, and C. R. Ball, reported the following nominations for officers of 
the Society for the year 1920 : 

President, F. S. Harris, Utah Agr. Expt. Sta. 

First Vice-President, C. G. Williams, Ohio Agr. Expt. Sta. 

Second Vice-President, H. W. Barre, South Carolina Agr. Expt. Sta. 

Secretary-Treasurer, Lyman Carrier, U. S. Dept. of Agriculture. 

Editor, C. W. Warburton, U. S. Dept. of Agriculture. 

On motion, it was voted that the Secretary-Treasurer be instructed to cast 
the ballot of the Society for these nominees for officers of the Society for the 
year 1920. 

On motion, it was voted that M. A. Carleton be made an honorary life mem- 
ber without dues, in recognition of his services in organizing the Society. 

On motion, it was voted that the programs of the annual meetings be pre- 
pared by a committee consisting of the Secretary-Treasurer as chairman, and 
two others to be appointed by the President, one member to represent the 
farm crops and one to represent the soils interests. C. R. Ball and C. A. 
Mooers were appointed on this committee for 1920. 

On motion, it was voted that the Executive Committee appoint a Board to 
serve in an advisory capacity to the Division of Biology and Agriculture of 
the National Research Council on matters affecting agronomists, this Board 
to consist of five members, each to serve five years. The first appointees are 
to be designated by lot to serve for one, two, three, four, and five years, re- 
spectively. The Chairman of the Board is to represent the American Society 
of Agronomy on the Division of Biology and Agriculture of the National Re- 
search Council. The following were appointed by the Executive Committee on 
this Board : 

C. V. Piper, chairman, to serve 5 years ; J. G. Lipman, to serve 4 years : John 
W. Gilmore, to serve 3 years ; L. E. Call, to serve 2 years ; and C. A. Mooers, 
to serve i year. 

On motion, it was voted that a committee of two be appointed by the Presi- 
dent to draft suitable resolutions on the death of Dr. Cyril G. Hopkins and 
that copies of these resolutions be transmitted to the bereaved family and to 
the University of Illinois and also printed in the Journal of the American 
Society of Agronomy. Dr. J. G. Lipman and Lyman Carrier were appointed on 
this committee. 

On motion, it was voted that the Program Committee be instructed to make 
the programs of the annual meetings as far as feasible symposiums around a 
central theme. 

On motion, it was voted that a series of resolutions introduced by E. O. 
Fippin regarding the calling of a national conference of persons interested in 
the use of lime in agriculture be referred to the Advisory Board on Agronomy 
previously mentioned, with power to act. 

On motion, it was voted that the Editor and Secretary-Treasurer be author- 
ized to admit advertising to the pages of the Journal of the American So- 
ciety OF Agronomy. 

On motion, the meeting adjourned. 



AGRONOMIC AFFAIRS. 



349 



REPORT OF THE COMMITTEE ON VARIETAL 
NOMENCLATURE. 

It is now eight years since the Committee on Varietal Nomenclature was ap- 
pointed. During this period, steady progress has been made. Classifications of 
three important cereals, oats, barley, and wheat, have been practically com- 
pleted to a workable stage. Of secondary crops, the sorghums are fairly well 
classified, while cowpeas and soybeans have received considerable study and 
the basis laid for classifications. 

During this period, the agronomists have shown an increasing interest in 
the matter and now generally recognize the need of a standardized nomen- 
clature. This has been aided by the movement in many States toward seed 
certification or registration and the need for standardizing varieties. Also, 
agronomists have come to realize that the enormous work on varietal testing 
which has been done in the past has given comparatively little satisfactory 
knowledge in regard to the adaptation of varieties, owing to the fact that the 
common names used have little meaning. Future work along this line should 
be on a sounder basis. 

Three years ago (December, 1916) the Committee suggested that the Society 
should take some steps officially to recognize standard names and further pro- 
vide some means by which new introductions might be correctly classified as 
to type and registered. For the classification and registration of new intro- 
ductions two plans were suggested, viz. : (a) that the Society appoint a com- 
^mittee for the purpose or (b) that the United States Department of Agriculture 
be approached with a request that an office be established especially to look 
after the work. No definite progress, however, was made. This was due 
partly, at least, to the war situation which demanded the attention of every 
one to other problems. 

In the general educational movement three steps were pointed out two years 
ago (December, 1917) : (i) The agronomists must be interested and trained 
in the work; (2) farmers must be interested, to the point where they would 
make some demand for the use of standardized names; and (3) seedsmen 
should be asked to cooperate and use the standard names. 

As a step in this direction the committee was authorized to open negotiations 
with officers of the American Seed Trade, to see what cooperation they might 
offer. Several approaches have been made to the seed trade. They appointed 
a committee on nomenclature, but it has failed to respond in any way. The 
indications are that the seed trade is not ready to cooperate as yet. This con- 
vinces the Committee that the agronomists must lead the way in the standard- 
ization of names and the improvement and introduction of standard varieties 
until the seed trade finds it to be " good business " to cooperate. 

Recommendations. 

In order to give the movement more definite direction the Committee wishes 
to make the following recommendations to the Society for consideration : 

To disband the present committee and form a new committee of five to ten 
members on the standardization of varieties, this committee to formulate a 



3 so JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



plan for the testing and comparison of the standard types and new introduc- 
tions. The functions of the Committee would be to : 

(1) Examine proposed classifications and adopt a satisfactory classification. 

(2) Propose changes or modifications in classification as occasion required. 

(3) Attempt to arrange with agronomists for the testing of all standard 
types wherever practical in order to determine their relative adaptation. In 
case of new introductions, it is expected that they would be tested against the 
best standard types for the region. For the purpose of testing types, the 
country would be divided into definite climatic or soil regions. 

(4) Appoint a subcommittee to identify and properly classify for seedsmen 
or agronomists, either old varieties or new introductions. 

(5) Take steps toward the proper registration and publication of new intro- 
ductions. 

To accomplish this last object it is believed that the first step would be to 
ask the Secretary of the United States Department of Agriculture or one of 
the agricultural colleges to provide a central office for this purpose. 



REPORT OF COMMITTEE ON STANDARDIZATION OF FIELD 

EXPERIMENTS. 

In the last few years this committee has made a thoro survey to get a com- 
prehensive view of the present status of field-plot experimentation, with special 
reference to methods employed by workers along this line. A bibliography and 
partial review of the literature of the subject has also been made. The infor- 
mation thus gained has been valuable. We have found out the various methods 
in practice and the views of many of the workers regarding the relative merits 
of different methods now employed in studying the same sort of problems in- 
volving the use of field plots both in soil fertility and crop improvement work. 

In giving further consideration to the matter this year, the Committee has 
been at a loss to know what to do next. The problems of standardization are 
by no means simple and it is felt that the Society should proceed slowly in 
making specific recommendations or standing sponsor for particular methods 
until more information concerning the relative accuracy and practicability is 
available. At any rate, this Committee has not been able to arrive at any con- 
clusions as to the best methods in any particular line. Comparative data are 
insufficient or entirely lacking. Different workers have obtained satisfactory 
results by different methods and no one can say which method is best. Much 
experimental work in comparing methods needs to be done before we can really 
say which methods are best and before this Society can be justified in adopting 
any particular standard procedure or in asking its members to follow any single 
practice as the best. 

To what extent is may be desirable to unify methods is still an open ques- 
tion. The best information we have suggests that complete standardization 
will not be practicable nor desirable. New workers will bring new ideas and 
individuality must not be unduly suppressed for fear of defeating the purposes 
of our science. Many important discoveries have been accidental, developing 
as sidelights and due to different methods of procedure. An increasing, num- 
ber of workers is engaged in experimenting in methods and we must look to 



AGRONOMIC AFFAIRS. 



the results of their work to point the way. Such experimentation should be 
undertaken wherever possible with the view to getting together a mass of data 
out of which at least a few fundamental standards may be formulated. A 
committee of this kind should be continued and its personnel should consist of 
men actively engaged in the study of methods. 

Additions to Bibliography. 

The following titles should be added to the bibliography of this subject pub- 
hshed in the December, 1917, and December, 1918, issues of the Journal of 
THE American Society of Agronomy: 

Arny, a. C, and Garber, R. J. Field technic in determining yields of plots of 
grain by the rod-row method. In Jour. Amer. Soc. Agron., 11, no. i, p. 
33-47. 1919- 

Arny. A. C, and Hayes, H. K. Experiments in field technic in plat tests. In 

Jour. Agr. Research, 15, no. 4, p. 251-262. 1918. 
Arny, A. C.., and Steinmetz, F. H. Field technic in determining yields of ex- 
perimental plots by the square-yard method. In Jour. Amer. Soc. Agron., 
II, no. 3, p. 81-106. 1919. 
Carrier, Lyman. A reason for the contradictory results in corn experiments. 

In Jour. Amer. Soc. Agron., 11, no. 3, p. 106-113. 1919. 
Christensen, H. R. Experiments in methods for determining the reaction of 

soils. In Soil Science, 4, 'no. 2, p. 1 15-178. 1917. 
Love, H. H. The experimental error in field trials. In Jour. Amer. Soc. 

Agron., II, no. 5, p. 212-216. 1919. 
Miyake, C. The experimental error in field trials and the effect on this error 
of various methods of sampling. In Ber. Ohara Inst. Landw. Forsch., i, 
no. I, p. 111-121. 1916. 
Waller, A. E., and Thatcher, L. E. Improved technic in preventing access 
of stray pollen. In Jour. Amer. Soc. Agron., 9, no. 4, p. 191-195. 1917. 

Respectfully submitted, 

A. T. Wiancko, 
F. S. Harris, 
S. C. Salmon, 

Committee. 



352 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



REPORT OF THE EDITOR. 

Altho the income of the Society from memberships was further curtailed be- 
cause of the large number of lapses and resignations and there has been some 
further increase in the cost of publication, the annual volume of the Journal 
OF THE American Society of Agronomy will equal in size that of 1918. In- 
cluding the December number, the volume will contain 356 pages, as compared 
with 360 pages last year, 432 pages in 1917, and 400 pages in 1916. Not includ- 
ing the December number, which will contain nothing except the President's 
address, the reports of committees, and the minutes of the annual meeting, the 
current volume included 35 papers contributed by 37 authors, representing 16 
States, the District of Columbia, and Canada. Next to the Federal Department 
of Agriculture, the leading source of contributions was the University of Min- 
nesota, 8 papers having come from the former and 6 from the latter. The vol- 
ume was illustrated with 10 plates and 14 text figures. 

Again the editor has to offer his apologies to the Society for certain short- 
comings which it has been impossible to avoid. Thru the greater part of the 
year he was far removed from the place of publication and from library facili- 
ties, so that there has been some delay in the handling of proof and of corre- 
spondence regarding manuscripts, and it has not always been possible to check 
or complete citations of literature. Thru the cooperation of the printers, prac- 
tically every issue has appeared on time, however, and now that the emergency 
work in which he was engaged is practically completed better service can be 
given. 

Beginning with the August number, an advance of some 35 to 40 percent in 
printing costs was effective. Until that time,, no change had been made in the 
rates since the original contract was made in 1913, except that charge was made 
for the advanced cost of paper. A proposition to take over the publication of 
the Journal has been made by another company and will be presented to the 
Society by the Secretary, but the Editor recommends the continuation of the 
present arrangement for reasons stated in a letter to the Secretary transmitting 
the proposition. The advanced cost of publication will result in a marked cur- 
tailment of the Journal unless the membership is largely increased in 1920. 



INDEX. 



Page. 

Aamodt, Olaf S., see Stakman, E, C. 

Adaptation of tepary bean 247 

Address, Changes of, 

78, 125, 170, 217, 306, 330 
Agronomic affairs, 

48, 78, 125, 170, 217, 306, 330 



Page. 



seed potatoes during 
age" 



stor- 



114 



259 
206 



33 



Alfalfa, Cross-pollination in 

American Husbandry, Review of. 

Arny, A. C, and Garber, R. J., 
paper on " Field technic in 
determining yields of plots 
of grain by the rod-row 
method " (Figs, i and 2) . . . 

Arny, A. C, and Steinmetz, F. H., 
paper on " Field technic in 
determining yields of ex- 
perimental plots by the 
square-yard method" (Figs. 
7-9) 81 

Association, Nitrogen relations of 

plants when grown in 49 

Auditing committee. Report of . . . 347 

Bean, Adaptation of white tepary. 247 
Bear, Firman E., and Ro3^ston, J. 
R., paper on " Nitrogen 

losses in urine " 319 

Biggar, H, Howard, paper on 
" The relation of certain ear 
characters to yield in corn " 230 

Blooming of wheat flowers 143 

Bolley, H. L., paper on " Official 

field-crop inspection " 196 

Breeding high-protein corn 309 

Burgess, J. L., paper on " Rela- 
tion of varying degrees of 
heat on the viability of 

seeds" 118 

Butler, O., paper on " Effect of 
wounds on loss of weight in 

potatoes " 304 

paper on " The effect of the 
environment on the loss of 
weight and germination of 



Carrier, Lyman, paper on "Ameir- 
can Husbandry, a much 
overlooked pubHcation " ... 206 
paper on " A reason for the 
contradictory results in corn 
experiments " 106 

Carrying capacity of range grasses 129 

Cereals, Lodging in 173 

Changes of address, 

78, 125, 170, 217, 306, 330 

Chlorides, Influence of, on plant 

growth I 

Climatic adaptations of the white 

tepary bean 247 

Committee, Seed stocks. Work of 221 
Standardization of field ex- 
periments 350 

Varietal nomenclature 349 

Community cotton improvement.. 121 

Conner, A. B., see Karper, R. E. 

Contradictory results of corn ex- 
periments. Reason for 106 

Cook, O. F., paper on " Experi- 
ments in spacing cotton " . . 299 

Control of flax wilt by seed selec- 
tion 291 

Corn experiments. Contradictory 

results of 106 

Corn, high-protein, Production of 309 
Relation of ear characters to 
yield of 230 

Cotton, Experiments in spacing . . 299 
improvement in North Caro- 
lina 121 

Crop tests, Error in 242 

Cross-pollination in alfalfa 259 

in milo 257 

Cutler, G. H., paper on " A dwarf 

wheat " 76 

Disbursements by the treasurer . . 345 



353 



354 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Page. 

Dwarfness in oats 72 

Dwarf wheat 76 

Ear characteds of corn, Relation 

of, to yield 230 

Editor, Report of the 351 

Effect of environment on seed po- 
tatoes during storage 114 

Error in crop tests from plat com- 
petition 242 

Experimental error in field trials, 

212, 235 

Experimental plots. Determining 

yields of 81 

Fertilization of wheat flowers .... 143 

Field crop inspection 196 

Field technic in determining yields 33 
Field trials, Experimental error in, 

212, 235 

Flax wilt. Control of, by seed se- 
lection 291 

Flowers, wheat. Blooming and 

fertilization of 143 

Funds collected by the treasurer.. 344 

Garber, R. J., and Olsen, P. J., 
paper on "A study of the 
relation of some morpho- 
logical characters to lodging 
in cereals" (PI. 6 and Figs, 

13 and 14) 173 

See also Arny, A. C. 

Grain, Varieties of, in Utah 163 

Grasses, Carrying capacity of range 129 

Hartwell, Burt L., paper on " The 
manurial value of a modi- 
fication of an orthoclase- 
bearing rock where only po- 
tassium was deficient " .... 327 

Hayes, H. K., and Garber, R. J., 
paper on " Synthetic pro- 
duction of high-protein corn 
in relation to breeding " 
(PI. 10) 309 

Hayes, H. K., and Stakman, E. 
C, paper on " Rust resist- 
ance of timothy " 87 

See also Stakman, E. C. 



Page. 

Heat, Effect of, on lime require- 
ments of soils 70 

Relation of, to viability of 
seeds 118 

Hendry, G. W., paper on " Cli- 
matic adaptations of the 
white tepary bean" (PI. 8) 247 

Husbandry, American 206 

Hutcheson, T. B., see Leighty, C. E, 

Influence of chlorides on plant 

growth I 

Karper, R. E., and Conner, A. B., 
paper on " Natural cross- 
pollination of milo " 257 

Karraker, P. E., paper on " What 
is the value of the usual 
laboratory work given in 
general soils courses?" 253 

Kiesselbach, T. A., paper on " Ex- 
perimental error in field 

trials" 235 

paper on " Plat competition as 
a source of error in crop 
tests " 245 

Laboratory work in soils courses. 253 
Leach, J. G., see Stakman, E. C. 
Leighty, C. E., and Hutcheson, T. 
B., paper on On the bloom- 
ing and fertihzation of 
wheat flowers" (Figs. 11 

and 12) 143 

Lime requirements of soils 70 

Literature of tillage 269 

Lodging of cereals 173 

Love, H. H., paper on " The ex- 
perimental error in field 
trials " 212 

Manurial value of orthoclase rock 327 
Market value of wheat in Utah . . 163 

Members deceased 217 

New 78, 125, 170, 217, 306, 330 

Reinstated 78, 125, 170, 217 

Resigned 78, 125, 170, 306 

Membership changes, 

78, 125, 170, 217, 306, 330 



INDEX. 



355 



Page. 

Milo, Natural cross-pollination in 257 
Minutes of the annual meeting . . 346 
Morphological characters, Relation 

of lodging in cereals to 173 

Natural cross-pollination in milo. 257 
New members, i 

78, 125, 170, 217, 306, 330 

Nitrogen losses in urine 3^9 

Nitrogen relations of plants 49 

Nominating committee, Report of 348 
North Carolina, Cotton improve- 
ment in 121 

North Dakota range grasses 129 

Notes and news.. 79, 171, 267, 307, 331 
Noyes, H. A., paper on " The 
effect of heat on the lime 

requirements of soils " . . . , 70 

Oakley, R. A., paper on " The 
work of the committee on 

seed stocks " 221 

Oats, Dwarfness in 72 

Officers elected for 1920 348 

Olsen, P. J., see Garber, R. J. 
Orthoclase rock, Manurial value of 327 



Piper, C. v., paper on "The words 
productivity, or productive- 
ness, and fertility " 342 

Plant growth. Influence of chlo- 
rides on I 

Plants, Nitrogen relations of 49 

Plat competition in crop tests 242 

Plat yields, Determining, by rod- 
row method 33 

Pollination in alfalfa 259 

in milo 257 

Potatoes, Etrect of storage en- 
vironment on seed 114 

Effect of wounds on loss of 
weight in 304 

Presidential address 

Productiveness and fertility 342 

Range grasses. Carrying capacity 

of 129 

Report of the editor 351 



Page. 

Report of the secretary-treasurer 

for 1918 126 

for 1919 344 

Reports of committees 349 

Review of tillage literature 269 

Rock, orthoclase, Manurial value 

of 327 

Rust resistant wheat 187 

Rust resistance of timothy 67 

Secretary-treasurer, Report of, for 

1918 126 

for 1919 344 

Seed selection to control flax wilt 291 

Seed stocks, Work of committee 

on 221 

Seeds, Viability of, as affected by 

heat 118 

Sewell, M. C, paper on " Tillage : 

a review of the literature". 269 

Shepperd, J. H., paper on " Carry- 
ing capacity of native range 
grasses in North Dakota " 
(Pis. 3-5 and Fig. 10) 129 

Soils courses. Laboratory work in 253 

Soils, Lime requirements of 70 

Spacing cotton 299 

Square-yard method of determin- 
ing plot yields 81 

Stakman, E, C, Hayes, H. K., 
Aamodt, Olaf S., and Leach, 
J. G., paper on " Controll- 
ing flax wilt by seed selec- 
tion " (PI. 9) 291 

See also Hayes, H. K. 

Standardization of field experi- 
ments, Report of committee 
on 350 

Steinmetz, F. H., see Arny, A. C. 

Stewart, George, paper on " The 
varieties of small grain and 
the market classes of wheat 
in Utah" 163 

Storage of seed potatoes 114 

Synthetic production of high- 
protein corn 309 

Tepary bean. Adaptation of 247 

Tillage, a review of the literature. 269 



356 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Page. 



Timothy, Rust resistance of .... . 67 
Tottingham, W. E., paper on " A 
preliminary study of the in- 
fluence of chlorides on the 
growth of certain agricul- 
tural plants " I 

Treasurer, Report of the 344 

Urine, Nitrogen losses in 319 

Utah, Varieties of small grain and 

market classes of wheat in. 163 

Varietal nomenclature, Report of 

committee on 349 

Varieties of small grain in Utah.. 163 
Viability of seeds as affected by 

heat 118 

Waldron, L. R., paper on " Cross- 
pollination in alfalfa" .... 259 
and Clark, J. A., paper on 
" Kota, a rust-resistant va- 
riety of common spring 
wheat" (PI. 7) 187 



Page. 

Warburton, C. W., paper on " The 
occurrence of dwarfness in 
ats " (PI. 2) 72 

Wheat, Blooming and fertilization- 

of 143 

Dwarf 76 

Kota, a rust-resistant variety. 187 
Market classes of, in Utali . . 163 
Winters, R. Y., paper on " Com- 
munity cotton improvement 



in North Carolina " 121 

Wounds, Effect of, on potatoes . . 304 
Wright, R. C, paper on " Nitro- 
gen relations of certain crop 
plants when grown alone 
and in association" (PI. i 
and Figs. 3-6) 40 

Yield of corn. Relation of ear 

characters to 230 

Yields of plots, Determining, by 

rod-row method 33 

by square-yard method 81 



VOLUME 11 



NUMBER 9 



JOURNAL 

OF THE 

American Society of Agronomy 



DECEMBER, 1919 



CONTENTS 

Taxing the Air for Increased Food Production (Presidential Address). J. G. 

LiPMAN 333 

The Words Productivity, or Productiveness, and Fertility as Applied to Agri- 
culture. C. V. Piper 342 

Agronomic Affairs. 

Report of the Secretary-Treasurer, — Minutes of the Twelfth Annual Meet- 
ing, — Report of the Committee on Varietal Nomenclature, — Report of the 
Committee on Standardization of Field Experiments, — Report of the Editor 344 

Index 353 



PUBLISHED BY THE SOCIETY 

4X NORTH QUEEN ST., LANCASTER, PA., 
and 

Washington, D. C. 



Issued December 31, 1919 



Acceptance for mailing at special rate of postage provided for in section 1103, Act of 
October 3, 1917, authorized on June 29, 1918 



JOURNAL 



OF THE 



American Society of Agronomy 

Issued Monthly except in June, July, and August. 



Editor 
C. W. WARBURTON 

Associate Editors 
Crops : CHARLES V. PIPER 
Soils: T. LYTTLETON LYON 

Assistant Editors 

Crop Production, C. A. MOOERS Soil Physics, L. E. CALL 

Crop Breeding, L. H. SMITH Soil Chemistry, W. P. KELLEY 

Crop Chemistry, R. W. THATCHER Soil Biology, J. G. LIPMAN 



MANUSCRIPTS 

Suitable articles concerned with instruction, demonstration, experimentation or 
research in agronomy will be accepted for publication. It is understood that articles 
submitted for publication have not appeared previously elsewhere and that they will not 
be offered for simultaneous publication in other journals without the consent of the 
Editor of the Journal of the American Society of Agronomy. 

Papers of any length, between I page and 30 or 40 pages, can be used. Personal 
and institutional items of agronomic interest, suitable for inclusion in " Notes and 
News," are solicited. 

To be accepted for publication, manuscripts should be original typewritten copies 
(not carbons) double- or triple-spaced, with wide margins. Special care should be 
g*iven to the proper indication of main heads and subheads in the text, to preparation 
and descriptions of tables, to citations of literature and to illustrations. For fuller 
details see recommendations on page 28 of volume 3 of Proceedings and examples in 
that and other volumes. 

All illustrations desired should accompany the manuscript, should be numbered 
and described, and referred to in the text. Line drawings must be made in India inlo 
and glossy velox prints of photographs are preferred for half-tones. 

REPRINTS 

Fifty reprints of each article will be furnished free. Additional copies will be sup- 
plied at a nominal charge. Covers on same paper as the publication with printed title 
page, 50 covers $1.00, and i cent for each additional copy. Orders for reprints and 
covers should be sent to the Editor immediately on receipt of proof of the article. 



AMERICAN SOCIETY OF AGRONOMY 



OFFICERS 

President 

First Vice-President 

Second Vice-President 

Secretary-Treasurer , 

COMMITTEES 

EXECUTIVE COMMITTEE 
Composed of the Officers of the Society 

COMMITTEE ON SOIL CLASSIFICATION AND MAPPING 
C. F. Marbut, chairman; F. J. Alway, E. O. Fippin. 

J. G. Mosier, C. a. Mooers. 

COMMITTEE ON STANDARDIZATION OF FIELD EXPERIMENTS 

A. T. WiANCKO, chairman; S. C. Salmon, F. S. Harris. 

COMMITTEE ON TERMINOLOGY 

Chables V. Piper, chairman; Carleton R. Ball, H. L. Shantz. 

Consulting Members 
L, C. CoRBETT, O. F. Cook. 



J. G. LiPMAN 

,F. S. Harris 
.A. B. Conner 
Lyman Carrier 



COMMITTEE ON VARIETAL NOMENCLATURE 
E. G. Montgomery, chairman; H. K. Hayes, W. C. Etheridge 



THE AMERICAN SOCIETY OF AGRONOMY 



OBJECT 

Article 11. The object of the Society shall be the increase and dissemination ol 
knowledge concerning soils and crops and the conditions affecting them. 

MEMBERSHIP 

Article IV. Membersli'p shall be of three kinds, active, associate and local. 
Active membership shall be limited to persons who are engaged in teaching agronomy 
or in scientific investigation in some branch of agronomy. Associate membership shall 
be composed of other persons interested in the object of the Society. Associate mem- 
bers shall be entitled to all the privileges of the Society except that of voting. Local 
members shall have no vote in the Society and shall not be entited to a copy of the 
printed proceedings without payment of an extra sum of money as provided in Article 
V of this Constitution. 

Active and associate membership may be secured by the endorsement in writing 
of some active member and upon approval by the President and Secretary and pay- 
ment of the annual dues. 

BY-LAWS 

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each local member $.50, which are due and payable on January i of the year for which 
membership is held. 

2. Any member in arrears for dues for more than one year shall thereby forfeit 
membership, but may be restored to membership without action of the Society upon 
the payment of such arrears. 

Applications for membership should be sent to the Secretary-Treasurer, preferably 
accompanied by remittance for dues, to save correspondence. 

PUBLICATIONS 

Proceedings. Four volumes of Proceedings have been issued, as follows: 

Vol. I, cloth, 238 pp., 39 papers, 1909. Vol. 3, cloth, 286 pp., 14 papers, 1911. 
Vol. 2, cloth, 154 pp., 16 papers, 1910. Vol. 4, cloth, 160 pp., 20 papers, 1912. 

Journal (continuing the Proceedings) : 
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